 "The viewpoints of saintly Torah authorities should never ever be subjected to ridicule."  Because ridicule might lead people to actually think about those views, rather than accept them blindly based on their having been espoused by "saintly Torah authorities." The ultimate denigration of an opinion is to place it above criticism-- it's nothing more than an admission that the opinion is not capable of surviving on its own merits. If a "saintly" authority's views can't stand a little humor, then one has to seriously question our views of sainthood. 