well if anyone does know what's out there then HN crowd would be a pretty good suspect in that regard.
I personally have done my fair share of consulting and prof services engagements - dozens of them across all kinds of industries - I've never seen a Haskell shop.
Java, Python, JS, Golang, Scala, Clojure, .Net, C, PHP - definitely out there in the field. Haskell - not so much.
Compare with how many Java consultancies do you think you can find on a quick search?
I don't think the Haskell development labor market is nearly liquid enough to rely on consultants. For full time jobs the picture is very different.
Then he'll have to look up some that he can't name off the top of his head? I can't name any Java consultancies, but I'm nonetheless confident that there are plenty...
With regard to Haskell, there are a lot of people interested in Haskell work compared to the number of positions presently available.
HN is a comically bad barometer for anything other than what's trendy in norcal.
I'd argue Python is much more prevalent with researchers than Haskell.
I'd say that people mostly do not know what is running in industry. It could be any share of anything. We get a hint looking at job offers; Haskell is small there, but not unheard of.
On the sweet spot, Haskell is great for modeling complex domains; it's great for long-lived mostly maintenance stuff, since refactoring is so easy; it tends to generate very reliable and reasonably fast (faster than Java/.Net) executables, but hinders complete correctness proofs and has some grave speed issues that can ruin your day if you hit them.
I would like to know how is it to manage a team of Haskell developers. I do expect it to be better than Java/.Net in forcing safe interfaces between developers (thus making it reasonably easy to survive a bad developer in a team), but I never saw it in practice.