I thin I have been clear about how I feel about it myself so I don't think I have anything to explain.

Here you'll find a link to a discussion on concertina.net on the subject 'Am I a musician' note the comment :

It's selfish, for a start. Most people that I know disapprove of selfishness.


on page three of the discussion and :

Music is a service, and you're a musician when you provide this service.

on the previous page, from where this angle took off.