It's a running joke that the Cowboys have flopped in the playoffs for decades, unable to recreate the magic of the Jimmy Johnson/Aikman era, but the answer is simpler than you think: Ownership. And no, I'm not talking just about Jerry Jones's ego and meddling.
In an episode of the Simpsons from November 1996, Bond-style villain Hank Scorpio attempts to purchase the Dallas Cowboys as a gift for his friend Homer Simpson, but has to settle for purchasing the (seemingly inferior) Denver Broncos.
Since that time, the Broncos have won three Super Bowls (1997, 1998, 2015) and made it at least to the conference championship twice more (2005, 2013). The Cowboys have even not made it to a conference championship since. That's right: Homer Simpson is a better owner than Jerry Jones.
Philly has managed to shake off its own Billy Penn curse, while watching their NFC East rivals flail around in high-publicity mud for almost 30 years. Here's hoping it continues this weekend. Go Niners. Phuck Dallas.