tl;dr - PK is a prickly pear and got into fights with a lot of people when they were new here. One of the things they did during those fights was link to posts and threads in /r/drama, where they are also an active user. This was incredibly shitty of them, and was made against the rules, so they have stopped linking to individual threads and posts. However, they still go to /r/drama to blow off steam. There is now a large contingent of /r/metanarchism who are convinced that he is nothing but a troll and hardly any better than the worst of the worst from /r/drama. However, since there wasn't enough specific evidence of clear wrongdoing after they stopped linking threads, and since there hasn't been a consensus on no-platforming /r/drama, all subsequent attempts to ban PK have failed and have caused the people they argue with most-frequently to perceive that a troll is being given leeway in the name of free speech. They perceive continued tolerance of PK to be an embrace of wishy-washy liberalism and at-best an indirect form of oppression. People like you and me see what PK actually writes and can't in good conscience sign on with that conclusion. And the cycle of drama continues infinitely.

Actual tl;dr - Pots calling kettles black, everywhere. It's not all tit-for-tat and some people involved are more reasonable than others. So far there hasn't been enough of a consensus to ban anyone involved.

edited for accuracy.