Lumping, for sure. There's people in the middle who recognize the difference between rap and jazz, but not the different variants within.
This is a special case of the observation that no discretization of a continuous space is "correct". They are inherently subjective, and some may be more useful for any given purpose than others.
Reminds me of a common review trope: "When it comes to X, people either love it or hate it, I'm somewhere in the middle"