If they don't want to perform live, they can find themselves another business model.
I think it's perfectly acceptable for a listener to not pay for digital music, and I also think it's perfectly acceptable for an artist to insist that a listener pay for digital music. I don't see the need for a "default" manner of doing things. Some may release things for free, others may insist on being paid for them. It should be up to the parties involved to decide which course of action might benefit them the most, and let the market decide which works. And yeah, much of the market has decided either "it's too expensive" or "screw you." A shrewd businessman at this point would lower the price, make their product more appealing to pay for, and/or not rely on recorded music as a significant income source.
As for other business models, the artist could sell t-shirts, do commissions, partner with other artists in various fields, etc. As a performer and composer of music that often finds itself in the general realm of classical, as well as in other genres that don't have a huge following or production mechanism, I need to be darn creative to have any hope of making a living, especially if I don't want to be tied to every whim of a big label, which would presume that the type of stuff I write is mass-marketable (doubtful). A person who insists on writing music that is not performed live does so with the realization that they have cut themselves off from the benefits that come with performing live music.
Heck, look at the internet! A huge portion of websites do not make money by people directly paying for what they do. I don't pay to read webcomics or Strongbad emails. However, I may buy a t-shirt of my favorite comic strip (of which I have purchased several as gifts over the past few years) or a Trogdor bumper sticker, or I may click on an advertisement on the site. The comic writers are not crying foul about people reading their strips for free.