It very much is. No where else in life are people forced to mixed with the general unfiltered public. "The real world" is highly filtered social circles and freedom of association. The idea that it's somehow an automatic good to force healthy kids to mix with everyone who happens to show up, regardless of whether they have severe behavioral or social issues, is pretty questionable.
> 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.
You can expose your kids to different cultures without leaving them wide open to everything else. It's not a binary. The point is that home schooling lets you pick and choose.