I hate that excuse, so much. It makes children sound stupid and unwilling to appreciate art and the world around them. I went on Pirates and HM as kids and guess what I loved them much more than dark rides that dumb down the story like your stupid, i think most people forget being a kid and having thoughts and at least some of us want everything to be at Pixar level quality story telling over "well its for kids so butt jokes and a basic message about being "good""
I say all art should challenge the viewer just a little, which is why the new versons of Pirates at Disneyland is kinda a joke, they want to eat thier cake and have it too.....look Pirates are cool and never did anything bad, its for kids and families so we should dumb the ride down because they don't know any better.