That's not completely true; they are fighting words, but they're fighting words re-used from the Culture Wars, which still rage on. (Particularly in academia.)
As far as the Sokal affair goes, it may or may not have done an excellent job of discrediting people, processes, institutions, writing styles, academic subculture ... but it did and could not touch any ideas.
In fact, you could even say that the Sokal hoax was an excellent validation/demonstration of many postmodern ideas, albeit at the expense of the same people teaching and regurgitating them.