I am playing my current warlock as evil. He is selfish and hungry for power and loves to goad the meat shields and especially that insufferably sheery cleric into putting themselves in danger rather than himself. He is also loyal to the group and does his part in and out of combat. He never takes more than his share of the treasure (although a couple dead meat shields or that insufferable cleric dying would boost his share...). He serves the Undying One, who is evil as all get out, but also hates Orcus, because everlasting life hates undeath.A good inquiry and I couldn't really say. In my experiences there certainly was a bit of youthful mindedness to disruptive play, but I’ve seen it in adults too. Probably a combination of experience and expectation instead of a singular source.