That's because in practice, "politics is the mind-killer" is the mind-killer.
If it is not too much trouble, could you explain further what you mean by that?
It seems to be treated as a thought stopper. "Do not go beyond this point." There are good reasons for it, but the behaviour looks just like shying away from a bad thought.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
(I plan to make these threads from now on. Downvote if you disapprove. If I miss one, feel free to do it yourself.)