I never realized how many people feel compelled to ask children why they aren't in school. I, personally, used to see kids out all the time and it never occurred to me to interrogate them or their parents. I always assumed they were either homeschooled or out of school for the day and ultimately none of my business.
We haven't had too much rudeness really, but you can see the shock on people's faces. We are a very busy family and I keep the kids moving. I don't see anything wrong with swinging by the grocery on the way home from a museum and I figure we have to eat, why not go out, so we're often spotted at local restaurants for lunch.
Our day often goes like this...
"I thought spring break was over..."
"yep, we homeschool"
"oh...(long pause) why aren't you schooling then?"
"we're done" or "we're taking the day off" or "we're doing it this evening insted" etc...