I'll answer that.

Socialization is a vital part of any child's development. Absolutely. But can you say that the only place a child would learn those skills is a public school? What in the public school experience transfers directly over to adult life?
It's interesting that you mention this because just this week my boys were told by a neighbor girl that they don't have enough friends due to the homeschooling. So I started listing off all the children that they spend at least 2 hours with per week in a cooperative activity of some kind. We were up over 20 very quickly; and that was limiting it to children within a year or so of their age.
The neighbor was insinuating that she has more friends, but does she really? Most people don't have it in them to be super close to more than just a few individuals at any one time, the rest are more distant friends or acquaintances. And if you're sitting in the same room listening to the same teacher working on the same assignment, can that time really be counted as socialization? I would say no.
Kids in schools are socializing on recess, before and after class, on the bus, and in extra-curricular activities. A lot of that time is pretty unsupervised - one or two adults per a hundred kids on the playground isn't exactly a high ratio.
Do I want other children (who by virtue of their age alone are immature and not fully developed) teaching my children how to behave, or do I want to be the one doing it? Naturally, the answer is me. I want to share my hard-earned wisdom and experience with my kids. Am I a control freak in some respects? Yup, roger that.
Am I saying that public schools are a cesspool from which no child will ever recover? Of course not. I used to teach and loved it; only reason I quit was because I was having twins. The homeschooling plan grew gradually from there.
What I am saying is that homeschooled children aren't by definition removed from society and locked away from all social interaction. That's a stereotype perpetuated by individuals who are hostile to the idea of homeschools. Are all homeschooled families all social and involved? No. But neither are public school children.
It's really not fair to claim that the method of schooling a family chooses is the one determiner of how their children will turn out.
In some respects, my children are more able to participate in activities and still retain some balance in life, since schoolwork is done faster at home (one adult to 4 children can work faster and on a more individualized basis than one adult to 22 or even 40 children), so they have time to rest every day. Public school children spend all day in school, then have homework and THEN have activities. That's really hard. We've got sports, Scouts, and church 5 or 6 nights a week but my children aren't taxed. They've got downtime and the ability to go out and play and entertain themselves every day after lessons are complete.
Again, none of this is meant to bash families who send their kids to school. I'm just pointing out the advantages that I enjoy as a homeschooler.
Is it exhausting? Sometimes it has been, due to the struggles my older boys have had with learning. It's gotten easier every year, and so far it's been super easy with my little guys. I do have to view it as though it were an actual job though. Otherwise I tend to get over committed.