As a Windows Phone Fan...
1) The carriers do not want multiple OSes to have to support. As Blackberry waned, the carriers only cared about having a foil against giving Apple a monopoly. BB couldn't do it (the storm and fire were flops) and MS pissed off all the carriers multiple times. I am also convinced Google and Samsung paid great sums of money to the carriers to keep Windows phone out of the market in the US.
2) While it's nice to try to pin it all on one person, the death of Nokia was a perfect example of corporate bungling: Great hardware, great OS with lots of features. What did I get for supporting Nokia and Windows Phone? Each year I received:
- Discontinued hardware (We had our Lumia 700's for 3 months when MS announced it wouldn't be bringing them forward).
- No new hardware or designs
- No new OS features. In fact, each upgrade they removed more and more of the great features we used. Each release was almost 2 years apart in Canada.
- No new look and feel - Come on MS, add some colors or themes or something. Did it really need to take 4 years to give us transparent tiles?
- Less apps every year.
All the while Android was getting more invasive... er I mean, more feature complete. Stephen didn't kill Nokia. Microsoft and Nokia were totally unable to keep existing users because they were more concerned about their bottom line than the users. The market never expanded because everyone that bought a Lumia wound up jumping ship a year later due to lack of many things that were basic features on other phones.
3) The death kneel as a user was when Netflix refused to support the platform. "Yes honey, Netflix can be streamed anywhere... except YOUR phone." Shortly after that the banks started pulling support for banking apps.