I agree with a part of this. Bledsoe is good enough to beat many teams. He's good enough to beat some good teams. But his weaknesses mean that he isn't going to beat any very good pressure teams....
So, what do you do? Play him anyway? If you play him, you'll finish 9-7 or 10-6, might make the playoffs, might even win a wild card playoff game, but then you are out. That wouldn't be a bad season. But is it really good enough?
It isn't an easy choice to go with Romo. There IS a very decent chance that with Romo, the Cowboys do even worse.
But at least we don't know Romo's ceiling yet. We don't know if by playing him, the Cowboys are incapable of beating the better pressure defenses (as we already know with Bledsoe).
Make no mistake about it, though. Bledsoe IS a big part of the reason why the Cowboys lost today.