Petition!
https://www.change.org/p/imdb-stop-imdb-from-disabling-the-message-boards
Help save the boards!!
Do you honestly think Amazon a world wide company worth billions and the owner of this site is going to care what a few hundred or even a few thousand say? They own this thing and probably are just tired of all the drama and harassment that goes on here. It's more than likely a good business decision.
Why not put effort into just getting other over to another place to talk?