Yes I agree. Also if you know your business won't need a lot of dev, like stuff like Instagram where I think they were still at 60 engineers even after hitting 1B active users, it can also be a good thing to use a niche (but viable) language to attract some bright engineers and they will be thrilled to be able to have a job to use it. Now I don't have such startup (yet) so I can't do it :)
I just wish ReScript would have gained traction and replaced Typescript. But who knows maybe it can still happen.
But I write software not to enjoy the process, but to solve business needs. And using Rescript, Scheme or Haskell drastically limits the talent pool and rises the cost. Which, BTW, can be very good for some businesses, that would want to hire only the best programmers anyway and are ready to pay for it. But that's some, not all.