It's a little simplistic, sure, but I mean how much nuance do you expect me to fit into a HN comment? What I left out is Windows Mobile, which was Microsoft's attempt to extend the Windows hegemony to mobile devices. Here are Windows Mobile's US market share numbers, per Wikipedia:

    2004 11%
    2005 17%
    2006 37%
    2007 42%
    2008 27%
    2009 15%
    2010  7%
    2011  3%

Somebody came up with better phone technology. Which would have happened anyways. Your argument was that it was necessary for Microsoft and now Apple to have a monopoly in order to create "necessity" for innovation, but Microsoft's monopoly was not driving Moore's law. The iPhone would have happened with or without Windows Mobile.