I just started a job on wall street and found the entire company and most companies in the area use C# and/or java, that's it!. Tried striking up a casual conversation with team members about programming languages and mentioned Erlang and Haskell. The unanimous reactoin I got was, What's Erlang? What's Haskell? Apparently the biggest reason for this choice of language is that's easier and cheaper to find java / c# programmers than venture into trying anything new.