No human is a troll
I have heard the WW board was the tipping point for Amazon. WW was to be HBO's gem, their long term money maker, therefore, Amazon's money maker. But there was so much negative feedback on the WW board, Amazon finally decided to factor the negativity into future losses on VOD rentals. In addition, WW just started, it may have many seasons to play out. Therefore, HBO and Amazon (IMDB) decided it was a good idea to shut down the boards, nip it in the bud, shut down the opposing opinion, and hedge future earnings on future seasons.
Think about it, if you spent a fortune on a website that directly promotes your product, would you really want an open forum on said website that denigrated your sometimes inferior product? It's amazing they didn't think of doing this sooner.