Corporations have only one duty and that is to return profit to their shareholders. Shareholders are already being taxed on a corporations profits via capital gains taxes and income taxes on dividends. Corporate tax is an unfair form of double taxation that is an unnecessary drag on our economy as both corporations and shareholders hire tax experts to minimize their tax burden making a visually progressive system appear less so. If taxes were easy to do an entire worthless industry could be eliminated and those intelligent individuals could be better employed to boost GDP.
Apple's tax practices - hiding money overseas to accumulate more wealth and get out of paying their share in their home country - are unethical, but unfortunately all too common. Large corporations and the very wealthy, basically those that are in the best position to give financial support to the nation, often seek and find tax shelters to keep money that should be going to society in their pockets, adding even more financial burden to the working class.