Again, to re-iterate, I don't want kids to be uncomfortable as a norm, but bashing up against other groups, cultures, opinions - finding your friends, finding people you dislike, learning how to work with social cues - all of this is important grounding for later life. What do you spend your life doing? Bashing up against other groups, cultures, opinions.
I also can't help but notice that amongst our friends who homeschool there is a very strong correlation between parents who didn't go to school and their kids not going to school. Around us this rarely seems to be about some kind of positive choice, mainly it's parent exudes strong "I didn't like school" vibes and kid picks it up and runs with it.
Creating silos where you closet away and attempt to "protect" people from the outside world has never, ever been good. Social Media (should) have taught us that.