Though the origins of FB are shady, Zuckerberg still deserves some credit IMHO. I will be blunt: building a social networking website is piece of cake. Designing it so that the users like it enough to use it on a regular basis, maintain it, and scale it are much harder.
History is full of stories of people taking advantage of other people's ideas. It sucks, I know. Let's face it: scientists, engineers, hackers are the tip of the spear, the guys taking all the bullets and all the risks. Business people are the smart ones coming in the 2nd wave, when the beach has already been secured, to reap most (if not all) the rewards. Some people, myself included, actually enjoy being in the trenches... and cannot imagine being a rear echelon pussy. To each his own. I probably won't ever be rich, but hopefully I will spend my life working on interesting projects...