Radio genre popularity goes in waves.. just like fashion.
Wait a few years, then a station will go 'only disco' and people will switch over to that one because it's something different.. then 12 other stations will change their format, too, to get in on the gravy train.
So that, then, all you hear is disco.
People will get tired of it in a year or so and it will go to the next genre.
Rinse, repeat, .. ad nausem.