He doesn’t want his music to be on a platform that is bankrolling someone who helps spread misinformation about vaccines. He suffered from Polio as a kid so this is something that means something on a personal level. That doesn’t seem that misguided to me.
And people have a right not to want to do business with a company that gave a hundred million dollars to someone producing misinformation.
Pretending this is a case of "spotify has an open platform that people can come speak on" is disingenuous, Spotify went out of their way and spent a ton of money to get the content he disapproves of on their platform.
(Comment aimed at a number of comments in this thread, including but not limited to the one I replied to)