[rjbwork]

I started programming C# professionally in 2013...the ecosystem has grown and been improved by leaps and bounds since then. I'm hopeful, personally.

I think one thing that keeps C# things from being implemented elsewhere is that there are just very different styles between even C# and Java. Some fancy libraries will do lots of reflectiony things, build syntax trees, and compile on the fly for performance, allowing complex configuration to be simplified and get fast code at runtime. There's also a big culture of LINQ/functional style, and fluent interfaces in libraries, etc. which doesn't seem to be present in something like the Java community (at least until streams), whereas more dynamic/weakly typed languages don't have, for obvious reasons, a culture of strong typing and letting the compiler do the work for you.

Then when you go to the hardcore functional languages like Haskell, ML, etc. you don't have a culture of OO much, not to mention they just aren't used much in production environments.

So, you see a lot of things from elsewhere ported and brought to C#/.NET, but not a lot of things moving from C# to other ecosystems.