There are a host of clubs and group activities that parents can involve their kids with such as sports, Boy Scouts, computer clubs, self-defense, summer camp, etc., where kids can still learn social skills by being around others. And they're far safer than government schools.
The problem is, it's not so much about being "around others," so much as it's about being around others who aren't like them.
You make my point with that all-important qualifier: "... parents can involve their kids." IOW, the parents are controlling their kids' interactions, leaving the kids with little opportunity to deal with situations on their own.