While I think this kind of panic over the state of conservatism's supposed intellectual bankruptcy is much hot air over nothing, there are important points to be made. The GOP is the minority party and thus it makes logical and rational sense for their elected representatives to focus their energies on proving why the majority party's proposals won't work than articulating and formulating alternatives. This, I believe, is the major contributor to the "atmosphere" that the Right is short on ideas.
The other major contributor is the past decade of GOP majority rule. The GOP had a big experiment with the "compassionate conservatism" of the Frums, Brooks and Kristols of the world during the George W. Bush years. To mixed results, at best. The collapse of the Bush infrastructure and the disillusionment of much of the GOP base with such big-government, big-spending Republicanism necessitates such soul-searching.
Other than that, I think McArdle has the best take when she writes:
The point is that no, Democrats do not always run away from their lunatic fringe, unless they are forced to by bad publicity. Which are the same conditions under which the Republicans have cleaned house every time. There is no party of perfect moderation in America. I confess that the Democrats seem more moderate to me, for the nonce. But that's possibly because they're currently in the majority, which means that moderates have been added onto the loyalist rump; and because people in my demographic tend to be Democrats.
If there's one iron law of politics, it's that no matter how crazy you are, people who agree with you always seem more reasonable than anyone else.