In honor of the Christmas spirit, I say "humbug".
If you helped build something and it grows and becomes successful, even after you (voluntarily) leave, why would you not be proud? And if you helped choose many of the players on the roster, and personally coached many of them as rookies, and helped them learn what it takes to become true professionals, wouldn't any decent person want them to continue to grow and succeed?
I think so and I think Bill Parcells loves the Cowboys and the year they are having!