Watterson stated many times that he was nothing like Calvin and his parents were nothing like that either. He just built the characters and then progressively explored their relationships as a way of reflecting on the pressures of modern society. It just so happened that he was exceedingly good at building realistic personalities.
Personally, C&H probably kept me alive as a teenager. When I was questioning the point of it all, Calvin’s sense of wonder and fearlessness injected some happiness into me, and I wished so hard that I could have been more like him growing up. I read a lot of it with my kids when they were very small, and then let them alone with it as they started reading on their own. They embraced the methods of Calvinball, which melts my heart when I watch them play. To them Calvin’s parents are silly in their worrying about worthless stuff like “washing”. If you didn’t notice certain things while reading it as a kid, chances are your child won’t either; that’s one of the marvels of this strip, like the best art it speaks in different ways to different people at different stages of their lives.