It may be because he's not a music critic.
Granderson hasn't confined his commentary to sport, however, so I think Fedor>all has a valid point here.
This is one of those columns you will agree with if you held the same opinion already, and won't if you didn't.
As you said, there really isn't anything new here.
Granderson is finding support for his argument where it doesn't exist. His description of the Gannon fight as "pretty close to a lynch mob environment" is silly. I doubt there were so many black guys in ball caps at hanging out at actual lynchings, and that any of those lynchings actually took place in a gym.