I was just looking at the status of IronPython, and it's on Python 3.4, which has been end-of-life for nearly five years. I'm not sure that indicates practical usability for most developers. Only C#, VB, and maybe F# actually seem like a safe choice on .NET. (PowerShell too, but that's a different use case.) So, just because something has been, or can be, done "in theory" doesn't mean all that much.

Unless you were intending this as a criticism of .NET?

I could see WASM actually pulling this off.