Perl is not that good a language though for practical purposes. The same way, a breadboard contraption is not what you want to ship as your hardware product, but without it, and the mistakes made and addressed while tinkering with it, the sleek consumer-grade PCB won't be possible to design.
Idk about Haskell, but I used Erlang which is also purely functional. No matter how long I used it and tried to appreciate its elegance, it became clear this isn't a convenient way to do things generally. But it was designed well, unlike Scala.