Self publishing has the potential to obliterate non fiction. Without a publishing house to fund actual research that takes months or years to complete I don't see a lot of people producing quality research based text. You make a good point about good books often not selling well but shouldering promotion and editing while also presumably working so you don't starve is unrealistic. The publishers are a necessary evil and so are record labels and movie studios. Strip out all the protections afforded by a big guy with money in your corner and you get 50 Shades of Grey and the YouPorn of erotica kleinbl00 mentioned. It's nice to have the gatekeepers weakened so a potential talent isn't overlooked but tossing them out completely is at the bare minimum foolish. Since I mentioned record labels, where are all the Internet musicians making it big with direct distribution and YouTube promotion? I can think of one and his name is Justin Bieber.