"..a healthy community hand-picked by parents is not "the real world" though, is it?"

School isn't their only exposure to life. You will get exposure to other people and non-healthy people outside of school.

"Kids in public school are exposed to society at large, in both good and bad ways. My kids are in class with others of different cultures and lived experience and I believe that enriches their lives. Despite, yes, there being some problematic kids in th"

When I was a kid, I was exposed to kids that should have been in prison..and many of them ended up there. My life probably would have been better if they weren't there.

"My kids are in class with others of different cultures and lived experience and I believe that enriches their lives. Despite, yes, there being some problematic kids in there."

This can still be done with home schooling.

"The sad reality of parenting is that you're never going to be able to hand-pick your child's experience all the way through life. Sooner or later they're going to be exposed to the "hostile flowers" you describe."

I disagree. If someone is hostile and aggressive all the time, I wouldn't be around them as an adult. I hand pick my friends, and you probably do too. I also still get exposed to the assholes of the world.

"Personally I think learning to be around those people and still thrive is a part of childhood that prepares you well for adulthood. It may be more valuable than some of the academic work kids do."

If you are at work and someone is sexually harassing all of the women there or generally causing issues for everyone around them (preventing most other people from getting their work done). Do you think they should stay, so everyone can learn to be around them?

You seem to think everyone is a reasonable person that might just have a few issues. This is far from the truth and many times, public schools will just keep these kids there, preventing everyone around them from learning.

It's also a burden to the teachers and staff.