Not to mention the fact that a massive part of school is just learning to socialize with people who aren't your family and that you may or may not particularly like.
I definitely got better at socializing when I left school and started to interact with much more age diverse groups in the wider world.
Especially with girls it’s important for kids to learn self esteem and agency, and they can’t do that when bigger, stronger, smarter and faster older kids are dominating everything in the classroom.
With that reasoning, you could also decide that classes shouldn't be mixed-gender, because boys might bully girl or girls might bully boys, and it's better to keep everyone in a group of people exactly like them.
Educators are finding that mixing genders actually puts a lot of pressure on boys to behave like girls, ie less excited etc so when they act out, they are medicated or sent to the principals office. Separating boys from girls in the classroom might help boys when they are younger.
And girls benefit from being separated especially during puberty. My friend just sent her daughter to an all-girls middle school that specifically targets girls this age so that they can learn to be more confident during the most awkward age of their lives.
Interactions, yes, but I wouldn't call those interactions socialising.
In my entire time as a child and teenager at multiple schools, I don't recall spending any time socialising with teachers and other faculty. Not once, and not even with my favourite teachers who made the most lasting impressions through their teaching, and willingness to teach me more advanced things than on the standard curriculum.
It was pretty minimal at university too. Socialising was with other students.
But the post by inglor_cz you replied to was specifically about socialising being limited to peer ages as a child, not social eduction in general.
Therefore your reply "this isn't really true though" and "how can you not categorise .. teachers" implied socialising with teachers and faculty, not just formal social interactions.
It really is true that many children don't have the opportunity to socialise with people outside a narrow age range at school, and that seems like a legitimate thing to dislike.
These are interactions, but form just a very limited subset of socializing. Most teachers remain fairly distant and unknown. Or at least that was my experience when going to school.
YMMV.
This is one thing home schooling has going for it, where the social life is built around activities with other home schooled kids who likely differ in age. It's much harder for kids to get caught up in the typical pet immaturities and stupidities of their age group.
Kids that have siblings, neighborhood friends, or social activities like boy scouts, which generally include children over a range of ages, really appreciate it.
It sounds like your school had access to this stuff already though, do you think it was valuable?
In standard school, there are very rigid age-based hierarchies. Sixth graders rule over fifth graders, who rule over fourth graders. And the adults rule over all of them. And then you have the cliques, etc.
You'll find that such hierarchies do not exist in the homeschool world, and the kids are better for it. If the homeschool environment is religion-based, you'll probably find that the children do not know how to interact well with people in other religions, but you still have excellent interactions between age groups.
They all did pretty heavy extracurricular activities. Keep in mind that i met them in a particular time, either as a youth camp counselor or as a "street educator" (not really, basically i animated open physics classes with experiments/construction for kids, think Kiwico but free and with social settings).
They also were quite late in STEM, even those with engineers parents (definitely not the majority), but at least bilingual (i saw a 10 year old girl speaking 4 languages and playing violin better than i did). The most "advanced" i saw (at least in mathematics principles and understanding) where those with a formal musical education. Most of them could play at least one instrument, but those who understood underlying music principle were definitely more likely to "get" physics and engineering for some reasons. I think pattern recognition is definitely important for people to understand STEM work, and that can explain my limited, anecdotal data.
Another common point is that each of their familly were fairly religious (or spiritual rather), but not close-minded. I think around half were christian (not really defined), and the other half were more new-age. No Chomsky day for any of the famillies.
[edit] It's quite unfair from me, putting them in boxes like christian and new-age. Let say around half of them believed in a single entity we could call god creating the universe and guiding humanity, and the other half believing that the universe himself (or Nature, or the soul) guide them. I'm pretty sure one couple were active dualist proponents
Maybe these traits are specific to Christian homeschoolers and not homeschoolers in general, but frankly I have never met someone who was homeschooled because of secular, rather than religious reasons.
These last two years have changed my perspective. While the vast majority of people were bathing in hand sanitizer, hoarding toilet paper, locking themselves away in quarantine, and avoiding elevator buttons, the people who were least in tune with popular culture (Religious, rural, etc.) seemed like the most rational actors. In my opinion turning off the TV and ignoring mass media, sports, culture is probably the most healthy thing a person could do.
IME, the homeschooled people raised by people (homeschooled or not) to whom that description does not apply also do not tend to fit it, but people to whom (again, homeschooled themselves or not) that description does apply are overrepresented among those choosing homeschooling for their kids.