that's a joke.
first, every fanbase is optimistic in september. that's what being a fan is. if you're not, then your fandom is crap.
second, cowboys fans are more team-critical than pretty much any other ballclub's. we rip on the cowboys constantly, whether they're 4-12 or 13-3. whether they won that week or lost that week.
and finally, since you've been a member of this forum, the only decembers when dallas was out of playoff contention were the 2 years that romo was knocked out for the season.
No, it's not a joke. I'm a Steeler fan living in Texas. EVERY year Cowboys fans start the year by literally saying "We are going to win the superbowl this year". It matters not what their record was, or if anything about the team has changed in any significant way. Every damn year it's a chorus of "We're winning the Superbowl". In their minds, their players have to be the best in the league because they are Cowboys. Quincy Carter, Chad Hutchinson, Drew Henson, Stephen McGee, Brandon Weeden, Kellen Moore, Tony Romo and Dak Prescott. At some point in time Cowboys fans have honestly believed those guys were the best QB in the league and could not be convinced otherwise. That's not even including the re-treads like Kitna, Bledsoe, Testaverder, etc...
It's an illusion that sprang forth from one phrase in the 70's:
"They appear on television so often that their faces are as familiar to the public as presidents and movie stars. They are the Dallas Cowboys, "America's Team'"
It was narrator hyperbole that Cowboys fans took to heart. It has created this entitlement, like they actually believe they are America's team. The Steelers have more Lombardi trophies than any other team, but never do I start the season by saying "We are winning it all again this year". Roethlisberger is a HOF credential QB and never have I said he's the best QB in the game. Never has there been a point where I would have said "There is no QB I'd take over Roethlisberger". Being a fan of the winningest franchise in NFL history doesn't mean I'm required to take things for granted, buy into the hype, or preen around like a peac0ck. I know this despite the fact that my team isn't perennially lucky to finish 8-8. Cowboys fans don't know this. Thus, they are the most delusional fanbase in the league.