Ignorance. Bias against Microsoft. The usual self-righteous boycott of the evil Behemoth Corporate entity. And yes, .NET technologies are now more open-source. Visual Studio Code runs on all OS platforms. Visual Studio is set to be released on the MacOS, and on Linux distros subsequently. F# is an open source functional language, .NET Core also has been open-sourced. And yes, with Xamarin, you can build native Android or iOS apps. Most of the hate against Microsoft boils down to bias against the corporation.

Lol, the more I read these to-do tutorials, the more confusing they get...