Well, frankly there simply are some very not nice people in this world who do rude, horrible, despicable things or else why are any of us posting about them? How would one describe their behavior? How can one politely convey what is inherently distasteful, rude, obnoxious, off or otherwise bad without being so generic that no one can discern just how bad the behavior/person really is?
There are shades and nuances with words, that is why there are so many words, to lend clarity to our thoughts and experiences when we try to share them with others. I don't advocate a free for all name calling, that is not my point and that is not what is being done. Doing something foolish (or insert any other "bad term" here) does not automatically mean a person is a fool. It could have been one instance of bad judgement. Is that name calling? I don't think so. However, using descriptors isn't, in and of itself name-calling and impolite, just an efficient and clearer way to get the meaning across. At least that is how I view it.
Edited for Typo! Ack