They could have cut the game in half, ended on a cliffhanger, and have a super polished game.
I don't know, man. Having it end on a cliffhanger would probably make me more pissed off than a poor Act 3.
Cliffhangers are a time-honored practice to milk your customers for more money. It's a fair trade, consumers pay money for additional content because
they are invested.
It's the principle on which the whole concept of having a series is based on.
Of course, if you fuck it up, people will roast you, which is part of the unwritten agreement too.
Look at the Halo 2 cliffhanger. FINISH THE FIGHT was practically burned into my brain.