What I mean is writing a desktop application without falling back to using C# for all the front-end code and relegating F# to being a glorified DSL for data processing.
Microsoft doesn't believe anyone wants to make apps in F#; Visual Studio doesn't even come with templates for it. You're expected to use F# to write libraries like Fsharp.Data, and write your app code in C#.
If I wanted to code in C#, I'd code in C#, but I don't.