The cynical view is that the failure of House conservatives to mount a serious leadership challenge shows that they don’t really want to lead, because the current dynamic serves their purposes a lot better.
The way things have gone in major legislative battles over the past several years (such as with the debt ceiling, government funding bills, and the “fiscal cliff” tax deal) is that House conservatives have consistently voted against compromises. This has led House leadership to cut deals that can pass the House with the help of Democratic support.
This dynamic has allowed House conservatives to maintain a ruse. They can go back to their constituents and perpetuate the myth of themselves as brave freedom fighters standing up for conservative principles against a wobbly GOP leadership that’s gone native in the Washington swamp. Meanwhile, because House leadership cut deals, House conservatives didn’t have to deal with the consequences of bond markets freaking out because Congress never raised the debt limit, or of a taxpayer backlash because rates went up on all income levels once all of the Bush tax cuts expired.