It's understandable. Even for that movie it's very dark. I've never understood what it was meant to do for the story or character development. Seems like they just wanted to scare kids.
I remember reading somewere that kids love to be scared. Wonka was a pretty weird dude too. Fucking great movie. I can't bring myself to watch the J. Depp remake. There is no possible way it could live up to the original.
It doesn't even come close. Still a very interesting depiction, though. They definitely made sure there was a creative spin on it. Worth a view though on a slow day.