I mean, why should they? Clearly Google thinks how they do things is in the best interest of their shareholders. Maybe you could argue that contractors are detracting from shareholder value because their interests aren't aligned, but that's not the argument you're making.

What you're saying is, essentially, if a company is making a lot of money, then they should give that money to their employees. But the purpose of a company isn't to hire or pay people, it's to generate a return for your investors.