If they get enough complaints, they can decide to remove pretty much whatever they want to. It doesn't really have to be based on any ground that is laid out in a rule. If lots of people become offended by a video and ask that it be removed, they won't hesitate to remove it. There were 3 JTF videos on Jimmy's account that were removed, so that's why the account was permanently disabled.
The reasons there are still Nazi and other offensive videos on YouTube is because not enough people have complained about them.