It's honestly all ESPN. They cover the cowboys and all the geographically close to bristol teams (NE, NYG).
It's nothing against the Broncos. The rest of the attention is based on the players. For example, you would hear nothing about the Broncos, Redskins, Colts, Seahawks, Saints if it wasn't for Manning, RGIII, Luck, Wilson and Brees
ESPN is pretty tough to watch, with a lot of fluff and BS but they just gravitate to the main guys. No one would pay attention to the Minnesota Vikings if Peterson was not on the team and even then, it really took them being in contention.