And who made you the authority on what constitutes a Cowboys fan?
If a team known for going to the Super Bowl hasn't reached the pinnacle of its goals in more than 20 years, are we supposed to be happy about that?
Who do you think we are, the Cleveland Browns?
Cleveland Browns fans are merely happy with the "potential" of being good. Cowboys fans are happy when we are GREAT, meaning going to the Super Bowl and winning.
Are we supposed to be happy with losing or coming up short?
Therein lies the absurdity of your definition of "Cowboys fans."
Fans criticize players and coaches not simply because they just "don't like them" or they "hate" them. They criticize because they don't think those players or coaches can take us to the Super Bowl.
You have a simplistic way of looking at the world sans nuances.
And that's why you generally get bothered by people who aren't Pollyannish like you. And many people would GLADLY eat crow if Dak or Jason Garrett or whomever leads us to a Super Bowl win. That's what MOST fans would want.
But if we don't think they can deliver, we're going to say so because that is also encompassed in the definition of fan.