I don't think artists should be given a certain income level, but live performances aren't a garuntee of success. I pay for all of the music I consume. The last concert I went to was in 2003. I'm not a big concert guy. The bands I would want to listen to are only playing in a city, late on a week day night with bad traffic, poor parking. Its just not worth the effort. You have a much bigger audience that just wants to listen to music on demand. There essentially is no way to entice a customer like me to go to a show. The promotion of free music ends up being a lost sale, because that's what I really wanted in the first place the music, not the crappy stage show.
But like I said, its not a problem I created, nor one I can fix. A good number of musicians are just basically screwed. They'd be better advised to make a living some other way that pays better.