There are two pieces of context I think ought to be mentioned:
“post hog” and other “post your dick” variants are a canned /r/ChapoTrapHouse response against any user who seems like an unusually odious or bad faith wrecker or reactionary, like a rebuttal to 4chan’s “tits or gtfo”. It started when a neo-nazi went on CTH to spout race science but was mocked into posting his dick, which defused the guy completely; at the time, the subreddit was getting a lot of people like that, and “post hog” became one of the go-to responses because it was low-effort and it shut them down. It bewildered and frustrated people who were there say awful things or make users feel unsafe.
/u/randint has been on a crusade against hexbear for fucking weeks. He goes out of his way to stir shit and has explicitly admitted that his aim is to make the site look bad. Increasingly frustrated hexbears pointed out his bad faith engagement in the thread I linked. He goes about it in a bloodless, polite-sounding way, but he’s not there with good intentions. Only at the very end of the thread, deep in the exchange, did anyone give him the canned response, and it made him leave.