If nothing else, a lot of (containerized) .NET (web) services run on Linux. Also note that .NET apps can be packed as standalone (ignore the size) and as such are as any other standalone app.
You got some stats? The Debian stats say no one is using it on the desktop or traditional server stuff. I can believe Windows C# Dev are porting their closed service to Linux to improve, well, everything.
No stats, just what I see and consider logically. If you have a .NET (web) app, it makes sense to run it (for free) under Linux (directly or using docker/kubernetes/etc.) instead of paying Windows server license. Sadly I don’t see download counter for dotnet linux images but they would be some sort of an indicator. I can believe Desktop apps are not many, though, for historical reasons mostly. But now one can create a standalone nice looking app as well, perhaps they will be more frequent in future, who knows.
I think it will remain a Windows dev thing. Even if they sometimes use Linux as a runtime. Linux devs will use Python or something else. PHP is legacy really now. Go is popular for apps started at a certain time, but Rust seams to be replacing it. Which is good as Go is as Google as C# is MS.
