Um...60-80 fps is pretty damn good, Foundation. What do you consider "good fps", 150-200? 
Don't start complaining about low frame rate until you get down to <20. After that, it starts getting painful...
And how would you like a giant flying earwig forgotten beast (beware its poisonous gases!) to fly up your well shaft right into the middle of your hospital or meeting area and start slaughtering your dwarves?
Been there. Done that.
Well, OK, it wasn't a giant flying earwig. It was a ocean titan with two jackal heads (beware it's poisonous fangs!) that crawled up out of my cistern, into which it had fallen in several years before.
