Simple. Because its not the guys that the Tea Party helped elect who are the problem. Its the large group of moderate Republicans who, in many cases, nearly lost their seats to Tea Party primary opponents. We may not care much for these folks, but their votes still count in the House and Senate. "Letting it crash" as you proclaim, is simply surrender. If that's your choice, than so be it...surrender away. Many of us, however, have not yet begun to fight.
Surrender? No. Sometimes the only way to save the village is to burn it. If you are overrun, call in fire on your own position. The GOP is overrun with lesser liberals who couldn't beat the Democrat on the Democrat ticket.
These people who narrowly missed defeat last time will know it in the future, because they will have no Conservative votes.
They are the ones who will own this mess, and that's out there for all to see.
Or, they could always vote to do away with Obamacare.