I don't even hold it against him. He probably just realized that he can have a much more entertaining life (more speeches, more books sold, etc) by being more provocative and telling the New Yorker readers how wholesome their views are. I would myself certainly prefer that over a life spend between teaching Undergrads another decade the same models and fumble with statistics long enough to write another paper that explains the world.
I wouldn't go that far, though it's sort of a flawed analogy for comparison.
Economics generally is a field where lots of people hold on to their prior beliefs, and those beliefs are difficult to change, even in the face of new evidence and data. Even though most economists agree with each other about the basic sort of stuff that you learn in undergraduate classes, there's lots of disagreement when it comes to broader, value-judgement type questions. There's also a lot of disagreement about what data means that is difficult to resolve with more studies, and studies are hard because we can't do double-blind control trials of macroeconomic policy.
So, it's not necessarily unusual for economists to express crackpot-sounding opinions on matters of public interest without actually being crackpots within their field. Stiglitz has some weird ideas (I seem to remember he suggested the government should pay people to dig ditches and fill them back in to get out of the recession), and they may even be wrong (I myself don't really agree with him), but he's not a guy who just says stuff out of nowhere to provoke people like Ann Coulter.
