Haskell is already heavily used in finance, and they chose to go this route because all the feedback they were getting from financial firms wanting to use haskell. Your little bubble doesn't generalize to the whole world.
If by "heavily" you mean there are a few notable (and exciting!) projects out there, then sure. But what percentage of working quants code in Haskell ever? Probably <5%.
I don't see what that has to do with anything. You made a bizarre assumption that the financial world is hard for haskell to break into, when both history and the current behavior of financial firms says otherwise.
