From what I've studied, tyrannies often rely on control of people's sexuality as a way of zombifying people.
It's very common theory, however I don't believe in that. I think, dictators are not so clever, they are just people, who wish impose their world view and lifestyle on all people, and when someone follows by another way, dictators fly into a rage. So, it's not question of sexuality, it's question of control and power.