I don't follow.
After you would que it would put you right into the instance then?
Or would it just match you with a party you could meet on the overworld to try and follow deciphered maps? Because I think that would just fracture the playerbase further. Half of the players would try and form through PF and half through the DF. Even less would get done.

I think they're just not active because 2-3 player groups can clear them so most people just do it with their friends.