Being charitable, it seems to me that this is more a case of the word (phrase? acronym?) "NPC" having somewhat unfortunate connotations than of any direct malice being intended. For instance, if we take Eliezer's quote and replace "know yourself for an NPC" with "are aware that you have little chance of contributing directly to [our agenda]", we get something that's far less objectionable. Since replacing the word with the meaning shouldn't change anything if you're doing it right, I don't "NPC" was intended as anything more than a simple turn of phrase. The use of "NPC" simply strikes me as Eliezer's typical flair for drama, rather than some sort of deliberate snipe.