Uh, yes they were. It's just that then all these superheroes were clearly aimed at young children and not thought of as anything more than disposable cheap entertainment.
And no, the world's not a darker place than it was before, but thanks to modern news and the internet we hear a lot more about the state of the world than you did before. You wouldn't have heard as many stories about paedophiles in the 60s as you do today.