The reason Microsoft can't do this is because Windows penetration is absurdly high- something in the mid 90%s of all desktop computers. Any action like this would be followed by immediate litigation from competitors crying monopoly.
The reason Apple can get away with this is because contrary to what you would believe from reading the HN front page, apple's penetration in the cell phone market is minute and not a monopoly.
edit: for the person that said apple smartphone market share is 88%, its 14% worldwide, I don't know where you got your figures though you claim wikipedia:
http://techcrunch.com/2010/02/23/smartphone-iphone-sales-200...
Having a stranglehold of 95% on an entire industry (desktop pcs) is very different than owning 14% of a subset of an industry (mobile phones in general)