Why do corporation pay taxes is a good question in the first place. The same income is taxed twice - at corporate level first, and then when dividends are paid out (or, in case of buybacks, when shareholders give back their shares to Google in exchange for the profit that was already taxed). From what I've seen at my very cursory look at taxation policy textbooks, the official policy is that taxes don't have to make sense or be fair. They just have to be accepted enough by the population to not stir up trouble, and raise enough money for state to function. Hence the double taxation of corporate profits.