So ethical and loyal, these lefty artists. So blinded by the conviction that they alone are pure and good, they fail to recognise that their behaviour - rather than who they *think* they are - reveals them to be monstrous.
Why not simply continue the conversation privately? Argue in person or cut off ties if you really are so very 'shocked' and 'appalled'. The making-public of private conversations indicates only that you are unethical, disloyal and deeply calculating.