Good point. There is another side in here too: many people want to keep using the old systems they have learnt, instead of new better systems. Eg the backslash of Ribbon. It's pretty hard to innovate when on one wants anything to change.
I think that if something is better, then people will want it, steal it even. Take those un-skippable previews on some DVDs: people cite them as reasons to scrounge up pirate versions of DVDs. Oh, and how about those abominable "region codes" on DVDs? Are those "innovation" or merely a monopoly-enabled form of price fixing?
It's not clear, at least to me, that nobody wants Microsoft's innovations. I think it's more that they don't want them from Microsoft. Windows is a tough beast to change. The near ubiquity of the platform in the 90s and 00s means that there's a lot of people out there who "imprinted" on the Windows UI model.
It doesn't just affect Microsoft, though it may affect them disproportionately because of brand association. While OS X is a screaming success now, Apple's transition from OS 9 was anything but. It took 3 major revisions of the software before it was usable and a lot of people hated it at the time.
In contrast, Apple's introduction of iOS received a much warmer reception because there was no incumbent. Changing a major technology platform is hard.