One of the selling problems is that it can be hard to bring coworkers up to speed on it. Management don't like that kind of thing.

What management like very much is that using F# attracts better talent, but they no can believe.

It's actually very easy. If developers can't learn a slightly different language then they're getting paid too much.

F# is a highly different language (at least from Python and Typescript) with additional concepts and I don't think you appreciate the problem for most companies to hire developers at all, let alone the kind of people who can hit a new language without a speed bump.

I would think any developer worth his salary can pick up a new language in a couple of months at most.