Where 2k has Live beat is in the way players are presented. I loved how big the players looked on the court. I hate in live how Reggie Miller has the same body type as Ben Wallace...
I think once they got the ESPN license, that's when the "shift" happened. It was probably pretty pricey, and thus that money couldn't be used for whatever it was used for previously.
Also, when you want to acquire a licensed property, they often detail all the things they want included to show off their license. I'm sure ESPN wanted their presentation elements front and center as part of the deal.