I think it's more that the port of Windows to phones was so broken that they saw that there is no way they will get the platform into a stable state in the next year. It..just..so..broken.
I had a lumia 950 and with the crashes, lack of apps and UX horror I bought a OnePlus after 2 months amd never regreted it.
I heard that Windows Phone 7 was nice and everything went downhill with WP8 but I wouldnt know personally
WP10 is great these days. Switched from Android a few months back, to a Lumia 650, and will never go back to the bloated, resource heavy battery eater which is Android.
Fewer apps, turns out to be a pro, I've found. I'm realizing how much less distracted I am without every app and its dog installed. Also I'm realizing how well most things work via the web anyway (such as youtube), without requiring me to be logged in and sending rich tracking data to Google all the time.
Windows 10 Mobile is more stable than any version of Android I've ever used, and I carried Android from 2009 to 2016. Sure, it lacks apps, but it's just inherently a better written OS.
I had a lumia 950 and with the crashes, lack of apps and UX horror I bought a OnePlus after 2 months amd never regreted it.
I heard that Windows Phone 7 was nice and everything went downhill with WP8 but I wouldnt know personally