In the past producing and distributing music have been extremely expensive. As a result, large organizations have been created to handle those functions, and the organizations are powerful as a result of being large. These powerful organizations now face a problem, in that the conditions that led to their creation largely no longer exist. Professional recording is still expensive, but increasingly powerful tools are finding their way into the hands of consumers.
Distribution is a solved problem.
The music distributes itself, and in fact you'd have a hard time preventing it, as the industry is now discovering. In short, the technical producers of music offer less relative value than they did a decade ago, and the publishers and distributors of music have become altogether redundant. But these are still large and powerful organizations with large and bulging sacks of money, and they are completely dedicated to ensuring that more large, bulging sacks of money come into their hands. Since, initially, production and distribution were too expensive for artists to undertake themselves, producers and distributors defined the industry, even though technically speaking anyone could create content. For those whose work was not canonized by The Industry, their music might as well not exist at all from a commercial standpoint.