I’m afraid this might be a symptom of a sort of “thought crime”. Intimidation and ad-hominem arguments seem to be the weapon of choice for those that are essentially out of reasonable arguments.
While I understand that you’re addressing a principle which should apply to anyone, I am sorry to hear that Mr. Dreyfuss became the target of such a low level attack. Your father is a great man and a magnificent actor that brought a lot of happy moments to millions of people through the characters he played. At the end of the day this should matter more than any bullying campaign.