I don't think the argument lies with whether or not record labels provide a valuable service to their artists, they do, but more if the value of their services will remain above their cost. When they were the only distribution game in town, it was a no-brainer as you either distributed through them or you didn't distribute on any meaningful level at all. Now that there are more and more tools and services available to artists that replace some, and possibly soon all of the labels' functionality, the question becomes at what point does their cost outweigh their value?