My theory is that "Don't be evil" isn't sustainable if society defines "evil" as making business decisions in the interest of self preservation. Society likes underdogs, and Google is now clearly the top dog fighting to survive instead of fighting to get the top. Once a company gets big enough, it becomes easy to be perceived as a bully because anything you do will have all that power and leverage behind it. And underdog entering a new market is innovative. A big corporation entering a new market is invasive. Firefox supporting WebM is practical, but Google supporting WebM is evil. Even Apple is generally perceived to be the evil Big Brother they so famously advertised against a few decades ago.