This is an incredibly stupid takeaway. Facebook can hire the best software engineers and computer scientists in the world, so of course they hire such people and these people build stuff at Facebook.
That doesn't mean other people can't use Haskell to build web applications.
> That doesn't mean other people can't use Haskell to build web applications.
Very few companies do, though, so OP's point still stands.
This article would be a much better ad for Haskell if it weren't written by one of GHC's main author. The article also casts doubt on whether Haskell was picked because it's the best tool for the job or because of the team's familiarity with it.
Do you know a better language for implementing an eDSL that needs to be pure? Also familiarity does matter. With the requirement of needing a pure eDSL though I think Haskell would be the easiest path for most teams.
That doesn't mean other people can't use Haskell to build web applications.