Joy and creativity =/= gratuitous childishness. It's unfortunate this is lost on so many techies. My guess is it's a bit of smokescreen to avoid facing the endemic beta-maleness of the industry. Contrast with other fields--e.g., finance, at least, seems to remain a bastion of alpha males who are not short on humor, creativity, nor high-IQ, yet they don't have a culture of acting like overgrown 5-year-olds.