Well, it's gamified for a reason. Sure, I'll hang out on IRC and help folks, respond to questions on YouTube video tutorials I've posted, etc. I'm certainly altruistic to a point, but throw a number in front of me and it becomes a competition. Combine that with the fact that folks get to "win" against me by posting a shit answer and stealing my work, and I'm just not gonna play that kind of game. I'm not gonna learn anything posting intro to Java answers, now am I?

> That's true, if you care about the points, badges, etc.

Jeff Atwood has discussed this subject fairly extensively, and it does matter to a lot of people, which helps make SO more successful than it would otherwise be.