Absolutely agreed. Which is why I'm trying to specifically do that right now. (If it's not obvious, I'm the guy who delivered this speech.)
But I absolutely disagree that web developers can't impact poverty in Africa (or, maybe more importantly, in their own town). To be perfectly frank, I merely think most of us in this industry don't give a shit one way or another. Which is fine, but I'm perfectly happy to judge people all day long for thinking that way. ;-)