Still, concerts aside, a larger scale question is why is the young black community not into blues? It is rare to see any young blacks who understand or appreciate the music: for a huge percentage of them, rap and hip-hop are the only music, period.
Because Blues is not a music which preaches destructive behavior and anti-social gangsterism. It is not part of the culture which promotes rebellion against the "Man" the "System" etc. The Blues is a music appreciated by the mature and does not feature the Loud, heavy beat and sadistic lyrics the young want. Nor is it really a music to dance to. It is a music of reflection and introspection to a surprising degree. And tells stories.
And it is like asking why young whites don't like Frank Sinatra in being a generational thing.