All music is art - why should one genre be different in this respect than any other? Where one chooses to exercise that art and to what standard is up to the individual but as John P says - like a jeweler who wants the stone cut just right or the administrator who wants every detail nailed down, many musicians want to play really well-played music.

I sometimes get the impression that people who perform in public don't question or really understand their own motives in doing so. My guess is that most people start off performing in public with a high degree of (probably unconscious) narcissism. They want to be looked at, recognised and, briefly, in the spotlight. Nothing wrong with that. I still remember the very first time I sang and played in public (1965 if you're interested), and the ringing of the applause, sympathetic or otherwise, in my ears was a real rush. I was hooked. It was only much later that I realised that my real motive for performing in public should be to engage with and entertain the public - not my own ego. To do this, I had to know my stuff perfectly, think about what I played, how I played it, how I presented it - and I had to take in honest feedback about how it all went down.

If I'm sitting at home, strumming for myself, or family or a few friends, I can bugger about to my heart's content - it doesn't matter. (Actually, I work even harder at it at home - playing the same piece perhaps 50 or 60 times in a day to start getting it right). If I go out and engage with people, it's the engagement with those people - club, pub, singaround, session, paid, unpaid - that matters. The better I and the others engage, the more collective fun we have. You don't have to be a great performer to be a great entertainer but, no matter what, it's the moment that matters, not you or me or any of us. Getting it right - as far as you can - is a huge asset.