I imagine that, like most highly educated people, the people making these decisions do not think that the impact of Google employees on rent is their concern.

I imagine that, like most highly educated people, the people making these decisions do not think that the impact of Google employees on rent is their concern. This is because in a free market, housing is like any other good. Some people happen to be particularly affected when competition drives up the price of a given good. But it is not for individuals to try to mitigate this effect. The most efficient and fair outcome is for the government to redistribute money, and for the poor to spend their money however they feel is best. This is not libertarianism, it is basic economic theory that is shared by moderates on the left and right. So Google has no moral obligation, or indeed any good reason, to discourage their workers from living in SF.