a) what everyone else said, it's impossible to draw the line between what ordinary people do in all tax paying nations, i.e. look with a keen eye at all the possible deductions and tax incentives available to them in order to minimize how much they pay, and what huge corporations like Apple do which is essentially the same but with a multitude more laws and lawyers.
b) even if you could draw the line and somehow say Apple was doing something "more evil" than normal tax avoidance, what's the point in petitioning the corporation to stop doing that? A corporation is sort of a money-hungry optimization machine without a soul and the outcome you get with it depends on the environment it exists in, as a matter of mechanical logic. Would you hold a counter protest to bees because they sting people? No, that would be silly, it's just in their nature to sting people. Would you picket the Borg for trying to take over your star system? No, it's pointless to try and guilt the Borg and even more so to try to force them to change by such appeals.