>>/29012/
That's not the only interpretation. It could be that what the sage considers worthless is the thread itself or some/most of the posts therein, and he doesn't want to extend its life/increase its public by bumping it to the top. In that case it could be said that the sage is saging at the sagee.
Polite sage to emphasize the point that expressing the politeness of sages is not a pleonastic exercise.