I agree that the conservative blogosphere has exacted a greater toll on the media. (It's telling that the New York Times, for instance, has landed in most troubling for bending over backwards towards the right--in the cases of Iraqi WMD and Wen Ho Lee.) But I think he's making too fine a distinction, and he goes way too easy on the liberal bloggers. Many of them are also guilty of glibly assaulting the credibility of the MSM. Of course, MSM institutions often deserve abuse, with their phony stabs at "even-handedness" and their failure to call the Bush administration's bull-shit. And these failures need to be pointed out. But the reckless, sweeping assault on important institutions--especially The New York Times and The Washington Post--that emanates from large swaths of the liberal blogosphere will have a devastating long-term effect. These are irreplaceable institutions.
I guess this is one of those "name some names damnit!" things. Look, I'm highly critical of individual elements of the mainstream media and of certain cultural aspects of the beltway media but I've never had any idea to tear down the basic institutions of newspapers. Generalizations are always going to fail us, which is why I can't defend liberal bloggers against such a generalized smear (so, name some names), but I've never seen most liberal bloggers making a "reckless, sweeping assault" on the Times and the Post. They aren't just institutions, they're outlets run (cough keller cough) and staffed (cough miller bumiller nagourney bruni cough) and published (cough pinch cough) by individuals.
Liberals tend to argue that the Times and Post are far from the "liberal" reputation that they have and they're far from flawless generally. It's silly conservatives and idiots like Jeff Jarvis who imagine that the cheeto eaters are going to replace journalism as we know it with reports on the quality of cheeto production.
Nonetheless, institutions only deserve the respect that they... well, deserve. Until Conrad Black bought it the Telegraph was a fine, if conservative-leaning, newspaper in Britain. It then became a pile of steaming crap. If idiots destroy institutions there's no reason to continue to respect them.