Truthfully, I think the supply of programmers with functional programming skills far outstrips the demand. I use FP languages on personal projects (most recently Clojure) all the time, but the day job is still programming in Java at a shop that is all Java, all the time.
Every time I suggest bringing a language like Scala or Clojure into the mix (where they would provide real benefits over Java), I always get the "And where will we find programmers to maintain the code you write?" line from management. The answer, of course, is that there are likely legions of programmers like me, who hack around with FP languages in their spare time but whose only 'professional' experience is in mainstream languages.
I suspect the real reason is that most management is just too risk-averse to consider using technology that isn't mainstream.
Every time I suggest bringing a language like Scala or Clojure into the mix (where they would provide real benefits over Java), I always get the "And where will we find programmers to maintain the code you write?" line from management. The answer, of course, is that there are likely legions of programmers like me, who hack around with FP languages in their spare time but whose only 'professional' experience is in mainstream languages.
I suspect the real reason is that most management is just too risk-averse to consider using technology that isn't mainstream.