How does this question ''should it be against the law to offend anyone'' violate community guidelines?

It probably wont, if it's posted in the Law&Ethics category.

It's certainly something an eleventeen year old

should know the answer to though.

Thats a Chat Violation Chat is not Allowed

Something doesn't have to be a violation, to get reported and removed. That's why there's an appeal process you can go through. Use the link below to appeal. Yes/No questions are not automatically chat violations.

You've obviously offended someone.

It's chat. Read the guidelines about chat. Questions must solicit fact-based answers. Asking whether something "should" or "shouldn't" be isn't fact-based. It's opinion-based. Soliciting opinion-based answers is expressly forbidden in the community guidelines. Maybe you should actually read them because this is a major point that Yahoo gives considerable attention to in them.

Because you're trying to start a chat/debate and not seeking actual information.