dude, who prefer what here ? southies will like southie languages. A bong will prefer bengali and a gujju will prefer his native language (lets say on an average person). There is nothing special about hindi here. It just happens to be another regionally "preferred" language. "Other" regional musicians make hindi film music since hindi is widely spoken in India and happens to be the "national language" (i prefer calling it "common language"). My observation is that bollywood has been influenced with modernization lately in music w.r.t the tunes (if you have heard to what is called 'pop' in the western world). Of course, I dont intend to spark a needless discussion. Hope there can be some unity in diversity, if thats what our social reformers and older generations called it.
