I have a bunch of siblings, all of us homeschooled. Between all of us, some are more "socialized" than others. You can't leave out the individual in this discussion.

In general, schools do a fine job. Do they do an exceptional job in every case? No. But most people who go to public schools end up with okay social skills. I really don't think the same can be said of home school kids. Or at least those same social skills will take dedicated work to develop and may not materialize until well into adulthood.