[delfinom]

C# has had mono which was open source and designed to be embedded, and now we have coreclr, which is also designed to be embedded, very easily. Meaning you can write critical parts of your engine in C/C++ but run C# for core gameplay logic and plugins/extensions.

The JVM isn't/wasn't the greatest to embed and it's kind of a lumbering beast even today.

Also you aren't embedding C#, but dotnet, with which you open yourself up to an entire ecosystem of languages (if you really want to write plugins in VB.NET or F# or IronPython), and a ecosystem of libraries and even Microsoft tooling that's way more polished than Oracle/Sun ever put out.