I agree. Perhaps another way to generalize it is to say: The ability to critique and improve the product of others is only loosely correlated to the ability to

I agree. Perhaps another way to generalize it is to say: The ability to critique and improve the product of others is only loosely correlated to the ability to produce a high level product yourself. Another place you can see this is in art production (written or visual, particularly). Many great art critics have only moderate ability as artists themselves.