Threads are more declarative threads than discussion threads. Most posts are people expressing what they thought of something or denouncing another opinion out of hand. There's very few discussions in the threads anymore and I think this is partly why. Comparing the three films could be an interesting topic to discuss but instead it's shut down and dismissed. The films didn't remind you of each other so let's put a kibosh on the premise.
And I'm not saying I'm not guilty of this as well but it's just something I'd like to see less of.

Each film was about an artist breaking off from the real world, in Birdman/Black Swan in the form of hallucinations/in Whiplash it was a conscious decision, as they strive to greatness. Again, I think calling Whiplash a remake is a major reach and your point that the theme is one that is common in many films (although I wouldn't say it's the main focus of most artist biopics) is interesting but I'd rather at least discuss the idea than simply dismiss it in a one line post.