it's really quite a silly line of reasoning. And it's been discussed ad nauseum on here. Just because I'm not a concert pianist does NOT mean I can't tell when a much better pianist hits a wrong note or messes up. I frequently can.
And just because you may not play the piano at all doesn't mean that you can't tell when I, only a moderate pianist, mess up. You may not know exactly WHY or exactly what I need to do to correct it, but you know I messed up. And when you hear me mess up the sacrament hymn week after week, you know it's time to call somebody new.
Yeah, I know I know ... where could we possibly find another competent pianist in our ward?!? Name one single person who could step in and play as well!!! How dare I/you!?!?!!