Doesn't Apple, like many major corporations, hold it's profits and "treasure chest" offshore in a way that they paying massive amounts of US tax on it?
Money earned overseas is often kept overseas, I believe the statements made by Tim Cook indicate that. The reason is as much to keep the money locally where they're building and buying stuff, as it is to avoid repeatedly running into tax and business regulations involved with moving money around the world.
Apple earns a lot of money here, though, and I don't believe anyone has made the claim Apple is shipping their money overseas that they earn here as a tax dodge. I could be wrong of course, but somebody is paying sales taxes somewhere. People are paying payroll taxes as well. Income off of Apple's banked money is taxed in whatever jurisdiction it is held, and of course every time Apple spends some of that money to invest in research or whatever else, they're taxed on that too.
But global businesses are going to have money globally, and it doesn't make a lot of sense consolidating it all in one place if you need to keep spending it in many places. Leave the income where you bring it in, and then spend it locally when you need it.