Like I said, it's the tax treatment that basically stopped growth companies giving dividends. I think that we should change said tax treatment and also make buybacks illegal but that's a bit more controversial.
In any case, for both G and FB, they'd need to do buybacks anyway because of their employee share programs.
Given a certain amount of money, spending it on stock buybacks vs spending it on dividends returns the same amount of money to each HOLDING shareholder.
In one case, they receive a small sum. In the other case, the value of their stock goes up.