I just wonder, cause sometimes I see songs and I go "Why would they even put that in RB?"
Most of the conversation in this thread has been about bigger names. Most of those WTF songs are from independent, basement-studio artists who just want to be in the game- and are much less likely to have significant legal council, or legal concerns. I just pass them a boilerplate licensing agreement and hardly anyone has any issue with it. They're also much more likely to have the stems on the same computer they were playing Minecraft on twenty minutes ago, so they can dodge that cost. For them, it's very much "why not"? As the names get bigger, you start getting reasons why not, and you wind up with the sort of black hole of medium-sized bands- too small for DLC, but too big to consistently appear in RBN.