If we're going to be frank, the Venn-Diagram of people who build F# tooling and libraries and the people who work for Microsoft in some capacity on F# are nearly a circle. No one would ever use F# divorced from .NET, and it's kind of a red-haired stepchild there.

It's a fun language to work in, with some neat features, but C# is gobbling up every compelling advantage inexorably.