Talk to an accountant with experience in dealing with tax both inside and outside the US, and watch them wither before your eyes when they describe the cacophony of the US taxation system. You gotta love a taxation system where everything changes depending on where something is sold versus where something is received versus where head office is, varying right down to the county level...

Most of the reason why Americans get so frothy about tax is because they've made it ridiculously complex to comply with.