The Krugman detractors seem to be of the opinion that Krugman is clueless, not that he advocated a recession or cheered on the disaster.

In this article, Krugman says that consumers need to spend more and that a housing bubble is one way to increase consumer spending. Perhaps he was not advocating a housing bubble, but he clearly didn't see a housing bubble as the terrible thing that it turned out to be. If he thought the policy was bad, he wouldn't have offered it as a solution.