And because roleplaying takes a hit. And because most, if not all, subesequent areas are inflated with mostly unecessary combat. This isn't rushed in the "glitch" and "unfinished content showing up where it shouldn't" sense, it's rushed in the "ok, it's near the end, let's just make the player kill a couple of hundreds of things so it gets labelled as epic and challenging".
Different perspectives. It's your prerogative to have that one, and it's mine to have a different one. To me, if a game who averages a healthy dose of combat and roleplaying suddenly drops most of its roleplaying and focuses much more on combat towards its end, it's a signal of not enough balanced development. The focus becomes uneven, and the way to end feels much more less developed and rushed.