So we've decided as a society that any opinion that doesn't conform to the majority needs to be silenced? Scary.
Do you believe hosting companies should be unable to decline customers? Should Amazon have to host the KKK? The Taliban? Someone who screwed them over by declaring bankruptcy after a big bill?
It just so happens enough people are doing so to create some market pressure. Spotify is simply reacting to that pressure as all businesses do.
Nobody is being silenced.