Where are the functional gui users?

There has been a lot of research into ways of creating guis in a functional language. There is libraries for push/pull frp, arrow based frp and probably other superior research too. Many people seem to agree this is the more native way yet just about everyone seems to be using imperative binding libraries such as gtk2hs and wxhaskell. Even places recommended as good tutorials teach binding to these plain imperative libraries. Why not guis based on FRP research?