The part about being proprietary is a bit disingenuous. For a long time, it de facto was. Mono was always the red-headed step child, and required a lot more eff

The part about being proprietary is a bit disingenuous. For a long time, it de facto was. Mono was always the red-headed step child, and required a lot more effort to run in production, so people didn't. This proprietary nature wasted C# "runway". There was nothing quite like C# and the tooling around version 2.0, but nowadays it's a lot less special. The ecosystem around a language is the most important part, not the language itself. While it feels great to finally run C# CI in containers thanks to .NET Core, it's a bit late to the party.