Why is ‘NPC’ an insult?

An 11-year-old boy is doing well after being stabbed at a Dollar Tree store in Mill Creek, Washington State. Dollar Tree is like a pound store and attracts poor folk. According to court documents the insult ‘NPC’ had been shouted at a man who has now been charged.

My husband didn’t even say ‘What?’ when I told him, so for information I resorted to Veronica, who not so long ago counted as a young person. I was little the wiser to learn that NPC stood for non-playable character (or non-player character). The reference is to computer games, in which NPCs are, as it were, extras not controlled by the players. The connotation is that the character has preset behaviour and dialogue. One game has an NPC called Griniblix the Spectator. The gist is that an NPC has unoriginal opinions not of his own making.

As an insult, NPC proved popular with some who aligned themselves with Donald Trump.