This is why I love doing FOH.
I know I'm no virtuoso musician and I've no dreams of being a rock star, but when an audience is applauding the musicians on stage I know that every note, every drum beat that they heard was the product of MY work. As long as the guys on stage can play the right notes I can make them sound great or shi1te, depending on how nice/annoying they were to me at sound check (assuming they turned up for sound check).
Ok, so I would never deliberately make a band sound bad.. but its surprising how many "musicians" don't seem to appreciate that what the audience actually hears is not them.