I have seen kids who were home schooled by very dedicated parents (not simply for religious reasons) and these kids were smarter than public school education. One family I am thinking of all 'graduated' early and were accepted into Ivy league colleges and went on to be very successful. I think these parents were exceptional and maybe not the rule. To be fair these kids seemed a bit different than their public school counterparts in that they could and would be happy to carry on a conversation with adults on many subjects. They did seem a bit socially different than the 'regular' kids because they did not play the same and had a more difficult time with kids their own ages.
At one time I would have agreed with Stan, things are changing now.
Today I see many young people researching and learning the best ways to home school for many reasons. As for the social parts of homeschooling, today public schools are required to allow homeschooled in for art, gym, band and so forth. Also many homeschooled also have their own socialization things going on.
I don't think homeschooling is the same as it was in the 70;s, 80;s or even 90;s, it is changing quite a bit. There are so many more resources out there now. It takes real dedication on the parents part to be successful.