@AccordionBruce
I know the answer there because Belly explained it. The agreements that bands sign with the major labels often say they can't put their music up anywhere except via that label.
And yes to Bandcamp! It's where I do most of my listening any given day.
But, as you already alluded to, it's for listening to artists that haven't signed to a major and they don't have an equivalent to Spotify letting me listen to all of the Inner Ocean artists in a genre on shuffle.