Unless Apple's going to start paying to keep the roads, energy infrastructure and primary education that keeps their business and staff going they better start paying up.
Well, legally it is if the tax code says it is (or multinational agreements say the tax code should say it is). And ethically, I don't see why an artificial entity which exists purely because governments are benevolent enough to bestow special privileges like limited liability upon its shareholders should carry less responsibility for the maintenance of the civil society required for its continued existence than the average person living in that country.