Of course some coups are ok. We usually use better labels, like the Velvet Revolution here. Dictator is a pejorative label for an absolute ruler who came to the power from nothing. The last Shah and his son today are just standard heirs to a standard royal system

Put lipstick on a pig all you want, buddy.

I don't need to put anything. People, rulers, regimes are not equal. Some are great, some suck. Great are those who respect the individual rights and freedoms etc., you defend the exact opposite group