There is no reason Nokia couldn't have had Meego and Android alongside Windows Phone.
Really? How will their marketing handle this? Imagine three entirely incompatible operating systems. Add to that, they need to sell Symbian for a few more years anyway.
Samsung and LG launch products with alternative OSs because they don't want to be caught out if OS preferences change.
OS preferences don't change just like that. You need apps in the app store. It gets harder if you've already spent money on paid apps. Also, Samsung has gotten nowhere with their alternative OSes.
Those products failed to gain traction and were abandoned.
Windows RT was lame and deserves to die. Windows Phone is by no yardstick dead yet. It is actually doing a better job than many expected.
Several OEMs tried Windows Phone and/or Windows RT.
Exactly what Nokia wants. Nokia has become _the windows phone_. As of now, Lumia accounts for 75% of windows phone sales.
Microsoft disappearing from mobile, it looks to me that
Microsoft is not disappearing from mobile. Lumia sold 7.4 million phones this quarter. Up from 5.5m and 4.4m earlier. How is this a failing company, or a failing product?