I use my .NET skills all the time at work. You can follow along with the vast majority of the code that I write, as it's on github, mostly in github.com/GoogleCloudPlatform/google-cloud-dotnet. (I do plenty of work that isn't coding of course.)
That's only been the case for the last few years, but it's made my life happier. Java is the only other language I know to any kind of production quality, and frankly I haven't kept up with the new versions as well as I'd like to.
Will C# ever be a "blessed" language in Google? Who knows. I'd be somewhat surprised, but stranger things have happened. For the moment, I'm very happy to "merely" make the Google Cloud Platform experience as awesome as I can for C# developers.