First the poll, then the argument.
Historically, Cowboys fans have a lot to be proud of, and I think most know this. So most of you probably don't need the upcoming history lesson. For anyone else, this is what's at stake when the Jets travel to Pittsburgh Sunday.
In 1971 (actually 1972, but for this post, we'll use the season, not the calendar year of the actual game), the Cowboys played in their second consecutive Super Bowl, joining the Chiefs and Packers as the only teams with two appearances. The team they beat in that game, the Dolphins, went to two more Super Bowls in a row, shoving the Cowboys et. al. down to second place and becoming the first team to reach three Big Games. The team the Dolphins beat in the second of those games, the Vikings, went to a second straight Super Bowl after that, giving them also three. The very next year, the Cowboys tied the two teams with their third appearance (losing to the Steelers).
That season, 1975, the eleventh Super Bowl, was the last to end without the Cowboys holding the record for most Super Bowl appearances.
Dallas became the first franchise to reach five Super Bowls the next year (again, losing to the Steelers). The Dolphins tied them in 1984, led by second year phenom Dan Marino, and haven't been since. The Dolphins lost to the 49ers, who caught fire as far as conference titles go, but still couldn't reach their fifth before the Cowboys broke their tie with the Dolphins and reached their sixth (and then seventh). At the same time the Steelers added their fifth appearance to tie the Dolphins and 49ers, the Cowboys added their eighth.
Prior to the 1992 season, the Dolphins and Cowboys were still tied, but since the first of three trips in the 90s, the Cowboys have stood alone at the top of the Super Bowl appearance leaderboard. By the third, they had such a large lead, it seemed like it might be a safe record. The Broncos added a fifth and sixth in rapid succession, but the Cowboys still had a two-appearance lead on them at that point.
However, as we're painfully aware, the Cowboys have not been back since. In that time, the Patriots have added appearances 2-6, while the Steelers have added six and seven.
So, that's what's at stake. There hasn't been a great season in a while, but there's still something the Cowboys as a franchise can look at with extreme pride, and that's having been the only team to ever reach eight Super Bowls. Their share of the record for wins (five) was passed two years ago by the Steelers, and now Pittsburgh is gunning to tie the Cowboys for an eighth appearance. If Dallas's place in the history of the NFL is significant to you Cowboys fans -- and I argue it should be -- you want the Jets to win Sunday, no matter how brash, hyped, and obnoxious they may be.
Of course, I'm assuming most Cowboys fans don't need to be told to root against the Steelers fans. Being bitter about two narrow four point losses in the 70s, keeping Dallas from being the team of the decade and the first with six (or seven!) titles is reason enough, especially for anyone alive to remember. But in case you need a reason and haven't yet thought of what Pro Football-Reference has to say about teams when you sort by Super Bowl appearances, there you go.