OK, some extrapolations from some of what you're saying:

(1) The academy feels it's in peril, is organized w/ philosophy as the queen, hence both gives weight to philosophy and doesn't want to imperil the academy by denigrating the queen, 'cause then they'd have to reorganize.
(2) People who dislike the "relativist" point but do feel committed to the importance of philosophy would have a motive both for (a) thinking the idea is dangerous because, being philosophical, hence important, it could motivate people to believe and do bad things and (b) thinking the idea is dangerous because it harms philosophy by getting in the way of correct philosophical points that could motivate people to believe and do good things.
(3) The esoteric philosophical point itself threatens philosophy. (No one has made the argument on this thread, but it would go: If you can't get beyond axioms to a set of facts that are "independent" of the axioms and that therefore can be used to test the axioms, then the various discourses and their axioms can take care of themselves and don't need philosophy to tell them about their grounds and conditions, since the point denies the existence of such grounds and conditions.)
(4) People (whether they care that the academy is in peril or not) want to draw on the philosophical point for authority, because they believe it justifies what they do.
(5) Sincere, thoughtful people such as dubdobdee and byebyepride, even if they're not likely to use the word "relativism," think the point and similar points provide support for the idea that nothing is decided irrevocably and conversations can be reopened. (Am I correct that you think this, or that you thought it seven years ago, anyway, and that Alex seemed to be thinking it back then when he was posting on the Derrida thread?)