Earlier this week, Business Insider reported that numerous families have grown frustrated with the education their children are receiving at AltSchool, an ambitious, venture-backed, San Francisco-based ed tech company that four years ago began opening physical grade schools and promising parents who signed up a personalized learning approach that would far surpass the standardized education their kids might otherwise receive.

It’s not just parents who have growing concerns about AltSchool, however. Educators also question whether AltSchool is the next best thing in education, or whether instead the for-profit company could hamper the prospects of the children with which it works, and those it might impact down the road.

Seemingly, exasperation with AltSchool has been building over the last year. It was then that the company — which had originally touted plans to expand its network of schools and classrooms, so students could move around seamlessly —  publicly switched gears, announcing it would instead license its nascent program to other schools that want to embrace more individualized techniques.

Frustration has more recently reached a boiling point, with one mother comparing her children to “guinea pigs” at the school in conversation with BI. The term echoes conversations that we’ve also had with a handful of  AltSchool families in recent months. At a recent birthday party attended by numerous families, one mother told us she’d pulled two children out of the program and placed them in a neighborhood public school; the rest of the parents in attendance said they were actively working to place their children elsewhere next fall. The biggest reason they cited was that their kids are falling behind academically. One mother, who asked not to be named, told us that in addition to paying yearly tuition of roughly $30,000, “We’re all spending a fortune on tutoring to supplement what our kids aren’t learning.” Another mother of two at AltSchool tells us she spoke recently to the head master of one of San Francisco’s toniest private schools, and he suggested to her that she transfer her children elsewhere if she’s hopes to see them admitted to the institution he oversees.

Compounding their anger was AltSchool’s surprise announcement recently that its existing network of schools, which had grown to seven locations, is now being pared back to just four — two in California and two in New York — owing to “challenges and opportunities” that have arisen behind the scenes, according to the school. They’ve been left wondering: Did AltSchool pull a bait-and-switch on families who signed up for the program, only to find that their loyalty to AltSchool was one-sided?

Asked about all of this unhappiness, Max Ventilla, the former Google executive who founded and runs the company,  tells us the decision to shrink AltSchool’s physical footprint can be traced to “greater demand than we were expecting” for AltSchool’s software, which it has already licensed to half a dozen private and public school systems, and for which it’s charging between $150 and $500 per student per year, depending on the size of the school. “Our motivation for reducing the number of schools is so we can deliver the highest-quality experiences at schools that remain and with our limited resources, grow [the software side of AltSchool’s business] faster than originally planned,” says Ventilla.

He adds that the decision to close locations in Palo Alto, San Francisco’s Dogpatch neighborhood, and New York City’s East Village, has nothing to do with the company’s finances, as recently reported in Bloomberg. AltSchool is about to close its Series C round, he says, even while it still has “$60 million in the bank and additional debt and funding we can draw on.”

Still, it’s a valid question whether AltSchool should already be productizing and selling its software to other schools. Right now, both insiders and outsiders suggest it’s too soon.

Jennifer Carolan is a co-founder and general partner at Reach Capital, a venture fund focused on early-stage education technology start-ups. She notes that from the outset, AltSchool marketed the kind of personalized approach to education that parents are hungry for and that builds on a decades-long trend away from one-size-fits-all schooling to schooling that’s more tailored to the needs of individual children. Still, she notes, personalized learning is “extremely challenging to implement well.”  Indeed, while Carolan spent time at AltSchool when it was getting off the ground and decided that while it had many innovative ideas, she worried then, and now, that the availability of capital to the company while it’s still iterating on its model may have led it to “scale prematurely.”

Reach chose not to invest, but other investors have dived in. In fact, AltSchool has so far raised $175 million, including from Facebook CEO Mark Zuckerberg and prominent venture firms, including Founders Fund and Andreessen Horowitz.

Paul France, an enthusiastic young educator who spent four years as a public school teacher before spending the next three years at AltSchool, also has his concerns, particularly about the brand of personalized learning that AltSchool, and other newer schools, are promoting. “When I first arrived at AltSchool, we were opening new schools. There were lots of cool people to talk with and very cool ideals floating around.” He thought the “whole premise of personalized learning was very intriguing.”

Three years later, France says, he came to feel drastically different about the approach. “We live in this individualistic society that values personalized learning right now, almost to a fault. It’s ‘me, me, me.’ But it’s not a solution to any real problem in education.” In fact, says France, who now teaches in Chicago, AltSchool and its ilk may be unwittingly hamstringing both students and teachers by both creating to much individualized content for students (“that’s not how social systems of jobs work,” he notes), as well as unduly burdening teachers, who are sometimes given unreal expectations to meet.

“There’s this assumption that every kid needs a different activity to meet their needs, and that by applying tech, one can simply send them individualized content through a video or activity card,” France says. “But that’s not necessarily true. It’s not best for kids to learn only through a video or other content that’s sent primarily for consumption. And tech that operates under this assumption really undermines educators and the value of good teaching.”

Ventilla acknowledges that AltSchool has had to rethink its approach to education.  When Altschool started out, he says, it was premised on being “operationally focused, focused on facilities, ensuring great teachers were hired, and dealing with admissions, customer support and service as problems arose, but not engaging in pedagogic experience. We weren’t focusing on how students and teachers engage. We figured instead that students would be well served if we got out of the way.”

What AltSchool found, he continues,  is “that wasn’t the case. If we want the experience to be student centered, the teachers and students and heads of schools needed more support within the four walls of the classroom.”

Ventilla insists that AltSchool — which currently employs 180 people, including educators, technologists, and business operations staff — has since worked out these kinks and seen a “massive improvement  in satisfaction of parents overall and progress that students are making with both academic and non-academic standards.”

Of the 30 children who graduated from AltSchool last year, says Ventilla, every one was accepted into their first- or second-choice school. He also says that 92 percent of families who’ve responded to questions about their experience at AltSchool say they are satisfied with their experience, up from 85 percent last year.

Two Bay Area families to which we were pointed underscore this sentiment. Sharon Grehan, an executive at Gilead Sciences, has a second grader enrolled at AltSchool, and though she’ll need to move him to a different location last year because of a school closure, she says her intention is to stay with AltSchool.

Explains Grehan of her attraction to the school, “The social emotional component is just as important, if not important important, than the academic component at Altschool, and that’s important to me. Before joining AltSchool three years ago, my son wouldn’t participate in a group, he wouldn’t interact with peers, he felt bad about himself. Now he loves life, he loves school, and he has lots of friends. The personalized education piece is very key for him.”

Grehan says she did have concerns last year, when she was receiving status reports from her son’s teachers at 11 p.m. at night. “I was worried about teacher burnout,” she says. But she says such posts, which get pushed to parents through an app called Stream, are fewer and farther between and now mostly include “updates on field trips, social events, and, periodically, things they want to communicate to me about [my son specifically], like about a fear that he has overcome, or something funny he did that they are tickled by.”

Another mother, Sandya Mysoor, who teaches bullying prevention and has daughters in second and fifth grade at the school, sound similarly committed to staying at AltSchool for the duration.”We knew we were rolling the dice” by signing up for a brand-new school, she says. “I didn’t know what would happen, but it was, ‘Let’s see how this goes.’”

There have been “tons of changes since,” says Mysoor, “but I’d say the changes they’ve made are typical, and play on the same track as any startup” that’s trying to improve its offering. “No school has gotten it exactly right, but our experience is [AltSchool is]  trying harder and deeper than other schools.”

Hopefully, the parents will feel as enthusiastic about the school as their children age, assuming the schools remain open. (Ventilla, whose own children attend AltSchool, says they will.)

We reached out to the head of the private school who we’d been told was less than enthusiastic about AltSchool. We asked if it was true that he had concerns about AltSchool graduates. He clarified his comments, saying that the school “looks at the background of applicants on a student by student basis,” but he added that “some” might have concerns about its curriculum.

“Schools are hard,” added this person, who asked not to be named. “Trying to develop good schools and good software are different enterprises. It may be hard to do both.”