Or maybe he's actually smart, as you would expect from a technically minded person, did the math and realized, that there ain't many good charitable organizations to give, nor that the for-profits are worse than charities in pursuing goals beneficial to mankind.
Such alternatives consider human problems as both a human problem and a technical one, and work with both.
This is exactly the point; I expect a technical mind to be at a high risk of seeing only one part of the problem.
Reality is of course much more complex. Enterpreneurs are limited by the fact that having a "human" opinion carries a high risk of damaging the stock value.
Note that I wouldn't certainly consider Elon Musk's social enterpreneurship. Kiva would be (it's just an example).
For how may be exceptional in their fields, some people may still have a narrow vision outside that (or no vision at all).
Specifically, Page is a technically-minded person who's showing not to be able to see outside of the strictly technical realm, so choosing between a charitable organization and a technological one, is not really a choice, because in his perspective, there's no such thing as the first option.
I was actually surprised (but not too much) that a person like him may have such narrow vision.