There have been requests to remove the post limit going all the way back to 2015. The supposed reason for the post limit was due to 1.0's horrible launch and state of the game and how the forums were being flooded with posts about it. This is obviously no longer the case, but they've never removed the post limit.

I made a similar request earlier this year and was greeted with derision from a few people. As SturmChurro pointed out, it brings a discussion to a jarring halt when you reach that limit. Forums are here for discussions. Post limits prevent discussions.

I doubt it will ever be removed, but if this is the thread that achieves that, I'm happy with that.