"we have concluded that IMDb's message boards are no longer providing a positive, useful experience for the vast majority..."

they don't explicitly say "we're shutting down because of trolls", but i think the message is pretty clear.

It's not clear at all. Probably what they mean is that out of every million unique hits, only a small fraction actually use the message boards. Meanwhile, the message boards, being dynamic, are expensive to host.

It's definitely expensive, but aren't they heavily AWS based? More importantly, aren't they an Amazon sub-company?? I understand that they could rearrange the resources elsewhere but I don't think, at least this time, it's a merely cash problem.

Yeah but that's corporate bullshit to avoid litigation by admitting there's a problem. As a company IMDB is not especially interested in movies or in the quality of the service they provide to users, only in maximizing the revenue stream from them. They have a very aggressive approach to gathering data; if any of your personal information shows up in their database it's virtually impossible to get it removed, for instance.

Right