So, I was banned from the discord chat, even though I didn't break any of the rules. The owner recognized this, but didn't add me back because I was, in his words, "No great loss".

But in all seriousness, you were banned from the Discord because of a combination of factors, mainly that you were trolling (asking why obvious bands weren't on MA), and you were being unnecessarily rude to other users, including mods, in the chat. I'll readily admit that you're young, and probably have a lot to learn, but your immediate first impression in the Discord leaves much to be desired there. If you want to know what Discord rules you specifically broke, we would broadly say that you broke the "keep discussions civil" and "don't be a jerk" rules.