Why did the forum die?
I answered that
Real question is why the forum hasn't gotten new life?
Competitive players like 4-loom feel they are going to be heavily moderated and eventually banned. Their ego won't let them stay quiet against forum authority especially when none of them have a competitive bone in their graal bodies.
Non-competetive players like Fulgore constantly get trashed for complaining with classics subpar development, so they don't see any good reason to post.
Graphics people post, but only during holiday submissions.
Trolls like Coco88 don't want that smoke with J and the gang.
So for now the community is stuck with GOAT as it's most active poster.