"Enough that the teachers' unions feel pressure, apparently, since they constantly spew hate speech at homeschoolers."
This is true most of the time....most homeschool families do an excellent job with their kids.
There is a small minority however who are incompetent at best and downright negligent at worst.
There are even some who claim to be homeschooling, but actually leave their kid home alone to take care of the house, or in some sad situations - to monitor the meth lab.
And a small member of high school teachers seduce their students. Both are sad situations. What do you propose? Regulating homeschoolers even more? I grew up in PA, which has the strictest homeschool laws anywhere except maybe CA. It seemed normal at the time. Now that I've lived in free-er states I wonder why my parents put up with it. Why is it the government's business to put a stamp of approval on parenting? Should we let the government monitor kitchens to make sure kids get healthy balanced meals?
Most homeschoolers are motivated to make their kids succeed. It's much easier for lazy parents to take the eight hours of free daycare, free transportation, and free food, than having the kid around. (I am NOT saying that all parents who send their kids to government schools are lazy and using daycare. Just talking about the subset you mentioned).