It's not smart to credit a QB with a team's playoff record. There's like an entire team, coaching staff, and front office involved, all of which we've been highly critical of in Dallas for some time.
To about face and then put it all on Romo is disingenuous.
Dallas plays a certain way with Romo to cover up weaknesses in other places. Historically this approach has gotten them to about .500.
When was the last foundational DT this team has had? What about playmaking LB or Safety who are leaders that stay on the field? Or DB that steps up and consistently makes plays in the secondary?
Outside of some streaks here and there, there's none of the above.
Same with RB's. Julius, Barber, Murray-- all make a brief splash then leave.
What we've had at the foundational positions is Romo and later Dez and Tyron. That combination alone is not enough to make a perennial contender.