An analogy: if you're running the zoo, the public's safety is your job for anyone who visits. It's of course also true that sometimes visitors act like idiots (and maybe should be prosecuted), and also that wild animals are not entirely predictable, but if the leopards are escaping, you're going to be judged for that.
Maybe because sometimes they're kids? You gotta kid-proof stuff in a zoo.
Also, punishment is a rather inefficient way to teach the public anything. The people who come through the gate tomorrow probably won't know about the punishment. It will often be easier to fix the environment.
Removing troublemakers probably does help in the short term and is a lot easier than punishing.
