Well, maybe it is time to admit that "the market" and its players are not a homogenous mass and as Colin Crouch (of Post-Democracy fame) puts it (paraphrasing):

Well, maybe it is time to admit that "the market" and its players are not a homogenous mass and as Colin Crouch (of Post-Democracy fame) puts it (paraphrasing): there is the market and acting outside of it and mostly by different rules there are the multinational big enterprises/corporations. Why should NOT different tax rules apply them? Is this an idea easily translated into laws? Probably not. Doable for sure. Btw, please do not "combine" those Mega-Corps with small companies... they are not the same and will not be in the future; it only helps to drive certain unrealistic fears benefiting those lobbying and looking FOR the loop holes around the world.