[Haskell-beginners] Enum Float and Double

Why are Float and Double Enums? It doesn't seem to achieve anything useful, other than creating confusion such as http://stackoverflow.com/questions/7290438/haskell-ranges-and-floats. I've seen some threads from several years ago pointing out numerous problems with any attempt at giving these instances a sensible definition, but no explanation as to why they were created in the first place, or why they haven't been removed since.