I'm not so sure if I agree with the self serving push. I mean sure, these guys want great engineers--in fact, Zuckerberg explicitly states that.
But also remember that Zuckerberg is now investing in young medical research and Gates has been a philanthropic investor for a long time--these guys are looking beyond their companies and show that they truly care about the world and solving the BIG problems that exist. They are literally world-serving through these investments.