[gospelwut]

It's also a complex network of scouts, producers, and the like. Sure, plenty of bands produce and self-promote. Plenty of bands put their stuff on sites like bandcamp which (IIRC) give close-to-all the sales to the artists (with MP3 v0 and FLAC options for consumers). Amazon's MP3 store also has similar distribution (albeit at a higher cut for Amazon).

Distribution is solved (even when you throw stuff like iTunes, etc). But, you're not going to get top producers, recording studio sessions (which aren't cheap), and other things necessary for mastering a "high production value" album.

As popular as indie music and listening to Stephin Merritt sing over an 8-track is, popular music is usually heavily produced/mastered. These costs are simply outside the ability of most people.

Sure, you could say they should "bootstrap" it (to use a popular term amongst programmers) or seek "angel investors". But, look at how many programmers work for big companies.

I've seen a few bands here and there promote strictly on MySpace and SongCloud and do well. Word of mouth can be powerful. But, they almost ultimately sign up with a big label to get access to resources.