If the music is good and sincere and the musician(s) are willing to pay dues (tour for little money, build a following, market themselve, etc.) it is possible to "be succesful" (what ever that may mean) and it may even be possible to "support yourself".
However, the chances of consistantly making a decent living (say $30,000 per year) are remote for all but a fortunate few.
When I was a full time musician "playing the music I wanted to play (originals, etc.) I lived at a poverty level. I was "artistically satisfied" but unhappy with my standard of living. When I later decided to "sell out" I made very good money (Vegas, etc.) but did not feel musically "fulfilled".
So what is "sucess"? Happiness or financial comfort?
I have now played "part time" for 23 years (after 7 years "full time"). My day job supports me and I can choose to play or record what ever music I want and if it doesn't pay well, I don't mind. I enjoy playing as much (if not more) than when I was young. For me, that is success.
I still play 3 gigs a week (in three different bands). Wednesday is a blues band ($50 per gig), Friday is a jazz band ($70 per gig) and Saturday is a "country club" band - the gigs aren't much fun but it pays $250 per gig. All the gig money I make goes into recording gear. (That explains the country club gig)
The point is, you need to find the right balance of musical satisfaction and "income". Life ain't always fair - but you need to create your own opportuities.
Gidge, I don't agree that most are in it for the sex and drugs, those things are simply in absence of a pension plan!!!!