There's only so many ways to dunk a basketball and it's all been done before. I think today's big stars would rather not copy Nique, MJ, Nance, Vince, etc. And the majority of fans think the props are lame.
The best (and really only good AS game) is baseball's. The game is still played true to form and you get to see all the biggest stars. In football, basketball, and hockey the players take it easy and don't play defense, so you're basically watching a loose scrimmage.