... two div winners play each other. 7 game series for division series, for championship series, and world series.

I think you need the two wild card spots to keep millions of more people involved in the season the final month or two. It is just better for the sport to have so many more people interested in what is happening. But just make the two wild cards play a 1 game play in. This may have been how they had it up to a couple years ago, I do not recall, but multiple wild card playoff births drives more fan action which is good long term for the sport.