My guess is the board got sick of his spamming every thread with the same made up nonsense and not really being part of the discourse. It is one thing to have a contrary opinion, it is another to basically walk into the middle of active conversations, change the subject, spam 12 messages in a row and basically annoy the hell out of everyone. He was a drain on the board and made half the threads completely unreadable. What's worse is he knew he was doing it and still did it even after he was banned once before. Since I know he is reading this let me be the first to say "here is hoping they banned your IP".Interesting to see him get banned. Wonder what the threshold was. I enjoyed the back an forth.
tl;dr: the same reason he was banned last time. He brings nothing of value he just throws molotov cocktails and talks out of his ass and even when proven wrong triples down just to be a bigger ass.