For people that like math, sure, why not. When implementing mathematical concepts, if you squint at Haskell code you can see the original formulas, which should make it easier for people used to this way of thinking.

EDIT:

I'm not implying it's useful just for programming "math stuff", after all, everything can be reduced to a mathematical problem - including game engines[1], web application frameworks[2], etc.

[1] http://www.cse.unsw.edu.au/~pls/thesis/munc-thesis.pdf [2] https://github.com/yesodweb/yesod