I'd say it's just the hubris of youth, and not limited to programmers. "Meh, what do the old geezers know? I'm here to disrupt eeeverything, because I know best

I'd say it's just the hubris of youth, and not limited to programmers. "Meh, what do the old geezers know? I'm here to disrupt eeeverything, because I know best, and I know that I know it! (...) Oh wait: did I repeat most of their mistakes?"