Why did act 4 only have 3 quests?

[Bashiok]

Whether Diablo II did it purposefully or not we very much like the feeling of accelerating toward the end of the game with gradually shorter acts as you go. I can't yet speak for actual play time vs. what Diablo II provided, although we aimed to hit the same amount of time, I think we're quite a bit over. In any case, we want the player to accele..

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