There was a slim chance that Windows Phone might have been able to overcome all this and establish itself in 2011, when Nokia’s partnership was announced. There was no chance at all by the time Microsoft bought Nokia in 2013. and so the write-down of that acquisition now comes as a matter of regret but not surprise. Windows Phone has failed to achieve enough scale to be attractive to developers: it is a third choice, or perhaps even fourth, after the greater appeal of just doing another iOS or Android project. There are fewer apps, and those that are there are later and have fewer features than those on iOS or Android. Consumers notice. Some people love their Windows Phones, but not nearly enough.
—Benedict Evans, Microsoft, Capitulation and The End of Windows Everywhere