We don't have superintelligence, we don't have the remote idea of how to get started on creating it, in all likelihood we don't even have the correct hardware for it or any idea what the correct hardware would look like. We also don't know whether it's achievable at all.
Deleted Comment
While maybe not strictly necessary per se, it's a great way to get a foot in the door, and provides a great way to foster advanced type systems and functional programming (I personally find it to be a really fun language to write in to boot).
Isn't that just a result of everyone being into Spark a few years ago?
I also believe that to be the case as an employee. Ie, being a generalist is probably -EV for your career but it feels safer so it's kind of a contrarian position to say "be a specialist".
That's why you don't optimise for it in a vacuum. You weigh the potential benefits of switching to Haskell versus the additional cost of maintaining/growing a Haskell team.
Of course, there is just more of them in the first place. The other effects that you describe might also be true but keep in mind what the base rates are.
How is it easier to find a Haskell developer vs finding a Java/Python/PHP developer?