I'm not even really making an argument for C#, more just what it signals for C#. I am not a C# lover (although I also don't really love love Go).

I think whimsicalism's point may be that, if C# isn't the tool of choice for this port, then that's the death knell of C#. The death knell isn't what kills it; that's the death blow. The death knell is sounded after it's dead. If C# wasn't the choice here, then C# is already dead.

That may be overstating how dead C# is. But I think it is accurate to whimsicalism's point.

That might be their point, but it’s a bad implication for why languages get picked

Languages are languages, so having lots of people to communicate with using them is pretty important. Most people don't want to learn Latin.