I say again:
Maybe it's time to come to terms with the fact that Jerry really doesn't have his sights set on the Big One. He craves relevance more than anything, and he owns what is arguably the NFL's marquee franchise. KC may have a higher profile for the moment, but year in and year out the Cowboys attract a fan following across a much larger geographic and demographic cross section.
Jerry realizes that a SB win may be a big deal, but if you have a huge, devoted fan base, all he needs is to stay competitive. His team hasn't come close to a SB for 27 years, but they stay in the hunt. And the Cowboys are a huge TV draw, appearing in national games far out of proportion to their success rate.
Relevance. Buzz. Media attention. Marquee games for a marquee franchise. That's obviously all they care about. And why not?