Sure. But most home schooling parents don't isolate their kids. They interact with people at church. They interact with people on sports teams. They interact with people on field trips. Often times, in high school at least, they'll take college (or junior college) classes, so they interact with people there. They have same-age friends, and presumably interact with them.

There are plenty of famous folks who've been home schooled, especially if you open it up to historical figures. Obviously being famous doesn't necessarily mean you're well-socialized, and a few anecdotal examples of home schooled people who didn't turn out to be total screwups doesn't disprove the existence of a <i>trend</i> towards screwups, but I think they do discount the idea that children who are educated at home are necessarily disadvantaged by that fact.

A few names:

George Washington
Ben Franklin
James Madison
Thomas Edison
Venus and Serenia Williams
Tim Tebow
Hayden Panettiere
Abigail Adams
Eleanor Roosevelt
Teddy Roosevelt