Because writ small this sort of thing is isomorphic to "Let me buy you a beer." (see armenarmen's post above for a great example). That's a friendly gesture of kindness and common cause, and it makes friends. Those are good things, right? It's happens also true that these gestures are almost always offered within some social group or another. They're both "nice" and "exclusionary" at the same time. Isn't our world a funny place?

Basically you don't like "Greek discount" because you're not Greek. But if you met DHH at a bar and he offered that beer, you'd take it, right?

But isn't that always going to be racist? Even in the case of DHH, honestly. A programmer meeting another programmer and doing favors for them that have nothing to do with programming?

I don't really think that I would feel the urge to offer someone a beer because I was aware of them as a programmer - but if they went to my high school? I don't think so, and I can't recall doing that, but I just might be misremembering. Would I take it? Of course, I like free stuff. I don't know if I'd offer it. That feels like a weird backslapping "this guy is alright, he listens to Black Flag" or "he's from Arkansas, woo pig!"

Of course, if I used rails, I would offer him a beer, but that's because I'd be showing up at the bar after a day of making a living off of his work:)