At what age should they stop performing, and why should they have to stop if they want to perform and people still want to listen to them? And if they’re forced to stop performing, does that mean people should be forced to stop listening to their music? I’m not being totally facetious, just trying to follow your logic.
IF we lived in a society that forced people to go to concerts you would have a point. But to make the assumption that everyone has 'Gracie's' taste or your taste is ridiculous ...
Do you apply the same 'standards' to writers? Painters? Do you want to see pictures of the people who write books to decided if they're sexy enough to read? Seems you've found a new definition of 'shallow'...
For me I'd rather go to a Leonard Cohen concert than watch any 10 bands composed of 20 year olds.