You’re absolutely right that the idea of a right to be free from discrimination quickly descends into utter incoherence, since it requires a subsequent distinction between “okay” discrimination and “bad” discrimination, and the whole idea collapses on itself.

That said, and this is more a commentary on the state of things than this post, but your argument is unlikely to convince or get a fair hearing from anyone inclined to disagree with you. But sometimes it’s still necessary to make the argument, if only to illuminate the line of reasoning for those inclined to agree.