It's not that Haskell can't be used by industry, it's just that the language has mostly been used by enthusiasts and academia (that's not a bad thing). No big companies have really committed to making Haskell industry focused. Facebook has dabbled in it and even made some improvements to the GHC compiler but I don't think they are replacing swaths of their tech with Haskell.
I agree with the "never has" part of the statement but a little skeptical on the "never will" cause we can't really predict that. I feel like the language itself has been picking up popularity in recent years so who knows.
We can't predict that, and maybe it will one day, but I think that's unlikely. Academics will continue to want and extend Haskell more and more, and it'll enter into a conflict I believe between pushing the typed lambda programming paradigm further into research territory and having a slow and stable industry base that favors backwards compatibility, stability and performance.
There might be a way to have both sustainably, but I'm not sure why we'd want that.
I really wouldn't mind seeing Haskell continue to innovate and be a trial for innovative features, and have another slower Haskell like language which slowly and carefully brings back those features into itself once they've been proven mature enough.
> having a slow and stable industry base that favors backwards compatibility, stability and performance
I feel as if GHC addresses backwards compatibility and stability fairly well with new language features being gated by language pragmas. [1]
I don't write much Haskell in production, and what I do write isn't very performance intensive, but GHC's been pretty impressive vs. other compilers with languages at a similar level of abstraction.
[1] Foldable/Traversable in Prelude was a relatively large breaking change, and it was handled in a way that minimized the impact to existing code while still advancing the language.
> Facebook has dabbled in it and even made some improvements to the GHC compiler but I don't think they are replacing swaths of their tech with Haskell.
Their anti-spam and messaging evaluation system, for the whole system, is written in Haskell.
I agree with the "never has" part of the statement but a little skeptical on the "never will" cause we can't really predict that. I feel like the language itself has been picking up popularity in recent years so who knows.