Good point -- except I don't think public schools solve the problem. I have never been to a public school (American), but the impression I get is that the kids in public schools manage to seperate themselves into groups, despite sitting in the same room all day. Also, from what little I know of the subject (almost nothing), this gets worse in the later grades. It may be that I am wrong.
I have had experience with homeschoolers, and while I have only met one(!) black homeschooling family, otherwise I think homeschoolers may be more used to getting along with people who hold diverse backgrounds and ideas than publicschoolers are. Most (not all) homeschoolers have contact with other homeschoolers. Many homeschoolers are weird. Vegitarians, vegans, christians, wiccans, unschoolers -- you name it. Also, homeschoolers tend to be used to getting along with people of many different ages--otherwise you wont have anyone to play with. Public schools are well known for careful stratification and segregation of age groups.
On the other hand, I haven't had a chance to meet the reclusive homeschoolers. They could be terrible.
I won't say that one is better than the other, but I won't let you say homeschooling is worse. Not without an argument, anyway. (And I wont say anything at all about private schools).