It's an easy choice if you're a publisher today wondering what kind of game you want to greenlight:
A) You pay lots of up-front money for league licensing rights, while competing in a relatively small market, alongside other franchises whose customers have 15 to 25 years of ingrained purchasing habits.
B) You create your own IP from scratch, own all the rights, and operate in a market that's much larger than the limited sports genre.
Option B makes the most sense, and the most cents. Especially with how much higher the costs are for making a 3D game in 2015 versus making a 3D game in 2005.