is not about the supernatural, its not really a cartoon about kids fighting monsters but about kids looking for truth.
"the world is full of grown-ups who lie to kids, and that it's up to those kids to figure out what those lies are and call them on it, even if there are other adults who believe those lies with every fiber of their being. And the way that you win isn't through supernatural powers, or even through fighting. The way that you win is by doing the most dangerous thing that any person being lied to by someone in power can do: You think."
Seen through the lense of late sixties idealism, Scooby-Doo becomes a cartoon in which the viewer is trained to understand that whatever the mystery, you just have to observe, ask questions, and think to come up with rational explanations. The monsters don't really exist, just bad people who want to make you too scared to look, let alone ask questions or think, so that they can take advantage. Against this backdrop Scooby-Doo
Addendum: There is also a nice discussion thread about this over at BoingBoing
