With that attitude you might as well just tell parents that they shouldn't participate in society!
If you allow a lot of people to pull away from that "forced" engagement with others then you start to stress a lot of societal bonds.
I don't know a single homeschooler that sits at home all day long. They work in family businesses, participate in bands, sports, and co-ops. Many belong to churches where families come from all different strata: our church has surgeons, line cooks, programmers, self-employed handymen, disabled vets. They interact with everyone—including kids. They do things like "kid markets" where they have a business. They watch their parents learn how the house works and how to manage finances.
There is no forced engagement—in fact the peer pressure is often completely gone. They are in an environment (their family) where they are much freer to be themselves.
Well, you wouldn't, would you?
Sorry, not to detract from your other points, but I thought it was funny.