I get what you're saying, but your only real argument here is Matty Ice as he's never won a SB. Brady has 3, Manning has 1. Once you get one of those, and certainly 3, all else is basically forgiven, at least for a long time.
Now, with Matty ice, you could argue that he has an elite team and still could not pull it off. Roddy White, Julio Jones, Gonzales, Turner, etc... and still blew it. But Matty was a high draft pick and has the premiere-in-waiting status, plus he plays for the Falcons, not the Cowboys.
But, I bet you hear some murmurs coming out of Atlanta if they haven't already about his performance in the clutch. He won't be immune to it.
What we have to do is not be so sensitive to the criticism Romo gets. He will have the opportunity to not seek another contract with the Boys in a year. It was his choice to re-sign a while ago and he will make the decision again here w/in the next year, unless franchised. He knows what kind of a team he has and if he still decides to sport the star for another 3-5, it will be on him. He's a big boy and can take care of himself and his legacy. It is not ours to defend.