And the thing is, while that's probably true in the collective, I'm not at all sure it is individually. After the past couple of election cycles, the House Republicans who are left are, by and large, the more extreme politicians representing the more extreme districts. Moderates in moderate districts tended to get swept away -- it's notable that even the relatively good Republicans who had previously survived in New England simply couldn't hold up against the "Republicans Are Crazy And Evil" meme that swept the land.
So look at the situation from the viewpoint of an ideological Republican who is representing an ideologically red district -- the types who make up a lot of the survivors in the House. Why in heaven's name would you compromise with those terrible Liberals who are now ruling the roost? You don't agree with their approach to government, and there is no electoral advantage to *you personally* to do so -- on the contrary, your core constituents are much more likely to string you up at election time if you appear to be working with Liberals. Especially because the hardcore right wing is arguing, persistently and loudly, that the recent wipeout was caused by Republicans being corrupted by compromise of principles in the name of power and influence.
Remember, every politician's first priority is to get *himself* re-elected. Sure, bringing the party back to power would be great, but it's a secondary goal. So what are your choices? You can be reasonable and moderate, compromise with the Democrats, and hope that it all works out so that your party looks good -- because if it doesn't work out, someone further to your right will eviscerate you in two years. Or you can stand on hard-right principles, knowing that whether you are right or wrong, standing on principle can *always* be defended when election time comes around. It's not the strongest possible argument, but it's usually good enough to get an incumbent re-elected.
Yes, it's rotten strategy for the party, and yes, it stands a high likelihood of marginalizing the Republicans for many years if the Democrats manage to turn things around in the next two years. But on the individual level it's pretty good strategy, likely to keep the jobs of most of the existing Republicans. And these are "every man for himself" times...