Let's not forget that these music services are possible because the authors are paid peanuts, i.e, almost nothing for their work (other than a handful of the most popular chart topping acts).
The thing with journalism is that you can't rely that much on back catalogs and artistic enthusiasm. An indie band might share all their music on Spotify for $1.37 a month revenue for the love of music, but that $1.37 will not buy you much of quality reporting...