I'm baffled by this. Many workplaces? Mass transit? Walking down the sidewalk? At a concert? Buying groceries? True, there don't all expose you to the full sweep of human existence at once but, in aggregate, it seems pretty similar to what you'd encounter at most public schools. What if they want a career in a hospital, or law enforcement, or social services, ... the list goes on.
You might hope that your child will live a privileged existence unbothered by the rabble, but it seems to me they need to be prepared for a future where they encounter all kinds of people. I'm sure this can be compatible with homeschooling but I can't see how it's not generally a disadvantage. (Though perhaps onerous clearly outweighed by other advantages, depending on the situation.)