Being a mediocre guitarist is probably easier than being a mediocre violinist; and writing a Facebook clone that works for a few million users is easier than writing a web search engine that supports comparable traffic. But when you are trying to expand the boundaries of what is possible, everything is hard, even things that seem easy when tried in their simplest form.
I've gained far more value from twitter, hacker news, facebook, etc than I have from most academic research that's been done on ... pick a topic.
Maybe I misread you, but you seemed to imply that good minds were being wasted working on social sites. I think this undervalues the ability to do things we know how to do, but to do it well and better than the rest. Apple is inventing new shit, but they make things better than everyone else. this adds enormous value to the world. Many hours of my life are saved because they paid attention and got a lot of details right. It's not science, but it's highly valuable.