Frankly, I found just the opposite. I used to joke if we were any more socialized we would never have time to do school.
With all the activities available to home school families today, unless the parents are antisocial and purposefully hiding in their homes, home schooled children are extremely socialized. There are co-op classes, team sports and other activities organized by home schooled parents and organizations.
However I did find my son was often impatient with the immaturity of his public schooled peers.
Thanks kalee, very interesting.