Hiring is another problem entirely. If you need lots of people very quickly it'll be hard for F# to compete with something else, but for every other case I don'

Hiring is another problem entirely. If you need lots of people very quickly it'll be hard for F# to compete with something else, but for every other case I don't think it's so clear cut. People that use and like F# really want to work with it, and are usually more experience programmers than people that know only C#. Thus, hiring for F# makes a great filter. Considering how hard interviewing and hiring is, having another signal is a good thing. Maybe building your startup that needs 100 new people every year on F# is a bad idea, but for enterprise projects that don't move much, it seems a reasonable choice.