The problem is that how the music industry collects and licenses music is a minefield. You cannot simply purchase a license for "all of Twitch to stream your music". If Twitch buys a license, it covers only a narrow circumstance. If a streamer on Twitch uses that music, well per the music industry they need a different type of license (and the cost of that is ridiculous). Their entire business model at this point seems to be based on how many people they can smash in court rather than being cooperative.
The problem is that how the music industry collects and licenses music is a minefield. You cannot simply purchase a license for "all of Twitch to stream your music". If Twitch buys a license, it covers only a narrow circumstance. If a streamer on Twitch uses that music, well per the music industry they need a different type of license (and the cost of that is ridiculous). Their entire business model at this point seems to be based on how many people they can smash in court rather than being cooperative.