In my experience, people who spend alot of time thinking about or studying a topic tend to create classifications that allow them to describe their subject with greater precision to others.

Just as I would not expect a biologist to only be able describe animals in terms of "kitty cats", "doggies", "birds" and "fish", I wouldn't expect a music critic, music historian, or even someone that has or listens to a great deal of music to limit themselves to "rock", "pop", "country" and "rap" when trying to describe what they enjoy to others