Windows phone's apps were built in C#, which arguably had also a deep pool of developers, and it didn't help. Visual Studio was also the arguably best IDE around at a time where XCode and Android's Eclipse plugin sucked hard, and still it mattered zilch. The real problem was market share and mind share, two factors in which Windows phone tanked bad.

For instance, Apple forced people to write iPhone apps in Objective-C for years and nobody avoided the platform because of that, even buying Macs and paying 99 dollars a year for the privilege of writing and selling iOS apps.