Not much. Really failing to see what market share has to do with relative quality, however. Good straw man argument, but Bush2000 and Golden Eagle are way ahead of you in the art of attacking Microsoft's competition.
I will grant you that Apple is superior in quality to MS, but they failed to capture the vast majority of computer users. In my opinion, Steve Jobs is no different from Bill Gates. Maybe only allowing his OS to work on his machines makes him a little worse.