Heather Cox Richardson's summary is concise and elegant:
Lately, political writers have called attention to the tendency of billionaire Elon Musk to refer to his political opponents as "NPCs." This term comes from the gaming world and refers to a nonplayer character, a character that follows a scripted path and cannot think or act on its own, and is there only to populate the world of the game for the actual players. Amanda Marcotte of Salon notes that Musk calls anyone with whom he disagrees an NPC, but that construction comes from the larger environment of the online right wing, whose members refer to anyone who opposes Donald Trump's agenda as an NPC.c.f. 'muggles'In The Cross Section, Paul Waldman notes that the point of the right wing's dehumanization of political opponents is to dismiss the pain they are inflicting. If the majority of Americans are not really human, toying with their lives isn't important&mdash'maybe it's even LOL funny to pretend to take a chainsaw to the programs on which people depend. "We are ants, or even less," Waldman writes, "bits of programming to be moved around at Elon's whim. Only he and the people who aspire to be like him are actors, decision-makers, molding the world to conform to their bold interplanetary vision."