Thank you! I think it's mainly a function of minority piled on top of minority. I'm just guessing, but I think the majority of people who use Godot want to use GDScript for it's simplicity. Of the C# people, most don't care about compiling it from source, less so on Linux. There might also be some residual perception that .NET doesn't mix well with Linux, even if that hasn't been true for quite some time. But mainly, I think it's a fundamental aspect of an open-source engine that isn't documented well. You can find how to compile this thing left and right, but it's almost always the vanilla version without .NET.