Establishment media types are innumerate. I doubt that more than a quarter could estimate the US GDP within 35%. The details of pro-Social Security versus anti-Social security arguments, or austerity versus expansionary arguments, are completely lost on them. (It’s possible that I am not as conversant with these arguments as I should be myself, though I think I am reasonably conversant, to be honest with you.)
So they gravitate towards whichever position is more in line with some fuzzier, more qualitative world view; that world view is often that the American middle-class is spoiled and needs tough love. They don’t want to starve the middle-class, they feel they owe it to them. This is about more than making money. I doubt Ruth Marcus or Joe Klein would lose their jobs or suffer a pay cut if they stopped fluffing Paul Ryan. I also think that they genuinely believe that the American middle-class needs to suffer. I am not attributing any malice to anyone here, quite the opposite.
It’s striking that so many economists—even conservative ones like Greg Mankiw and Martin Feldstein—supported the stimulus, albeit with caveats about how it wasn’t perfect and so on, while non-economist pundits were generally critical of it. This happened because economists were more likely to consider the quantitative details while punditubbies (EDIT: h/t) thought gubmint should tighten its belt when Real Murkins do.
I also don’t think establishment media types supported the Iraq War because they wanted to see Iraqis and American soldiers die (with some exceptions, Tom Friedman has explicitly stated that he wanted to tell Iraqi civilians to “suck on this”). They didn’t understand the complexities of a potential war, so they went with what felt good—spreading freedom, keeping America safe, showing the Muslim world some tough love, etc. In some cases, crass careerist or circus dog motivations came into play I am sure, but I bet some of these people honestly thought it was “the right thing to do”.
Most of the people we've put in charge of political discourse don't actually know very much at all about policy. Perhaps that's a trite point. What's more interesting is this link between ignorance of (or maybe lack of desire to discuss) the details of policy, no matter how important to the topic at hand, and the switching of the conversation instead to airy-fairy issues of narrative and morality and horse races. I imagine that mirrors the way most people talk about things they don't know a thing about.