There are levels of expressing yourself, though, aren't there? It is not a case of you do or you don't but that, whilst you can, to a degree, do so in many situations, some ways of expressing yourself are more 'comprehensive'!! And, for some, that expressing of oneself comes not in the playing or the music but in the so called 'stage-craft'. So, for some, they can get their needs met in different ways to me. For me, it's improvisation that floats my boat and that makes tribute bands a no go area by definition.
I am the opposite of Jus Lukin. I cannot just play anything. Most 'popular' music bores me rigid and, if I am bored, the audience knows I am bored (suffice to say, I couldn't play poker).