Spotify is totally free to bankroll Joe Rogan. Others are equally free to feel that this is a bad decision, to criticise it, and to withdraw support in the form of subscriptions or platform participation because they don’t want to contribute to it. Support for freedom of speech does not come with a requirement to support or share a platform with any particular example of speech.
Spotify can make a decision about what has more value to them in the long term. Subscribers and content producers can decide if funding and promoting Rogan is a dealbreaker for them. Thats’s all this comes down to - a business decision.
Personally the real crime here is that this has become an issue at all - thanks to Spotify’s frankly desperate attempt to become something other than a music streaming service. I have at no point been interested in Spotify providing podcasts; it’s already an active anti-feature for me, so “now we give some of your subscription to this asshole!!” isn't going to do much than tip me further in the direction of moving to another service.