The fact of the matter is also that Dallas' fanbase at present although considerable is made up primarily of die hards, the laymans and band wagoneers that jumped on the SS Invincible Cowboys of the early Ninties are some of the voters that helped ensure Dallas was sending 10 and 11 players to Hawaii, not that they didn't deserve it.
Every Super Bowl Champ experiences an influx of band wagon fans and since Dallas sustained such long and dominating success Dallas had a lingering influx of bandwagon fans most of whom fell away when the dynasty ended.
Converts obviously came aboard and Dallas enjoys a great and diverse fanbase but without recent championships the bandwagoneers, which are the equivalent of swing voters and independents, have not been there to aide Cowboy players with their post season travel plans.