Well it all depends on your ideas about taxation, society and the role of government.
It is true that huge corporations already "give back" a lot of the money they collected under various forms (income tax, VAT, etc.)
But if you think that the role of government is necessary, then you agree that it should collect taxe to exercise this role. And money is taken where money is. We tax corporations because they make benefits, and a benefit is just a way of saying that even after deducting everything they can think of, they still have money they don't need. So why not take a part of it and re-invest it elsewhere where it is needed ?
Ultimately there is no proper justification for any tax, except its necessity to let society fonction properly.