Have you ever noticed how the most powerful sexual fantasies are often the most transgressive? (I'm sure you can come up with your own favorite example). I think that's why those who are in power (the church and the state) are so afraid of sex. It undermines their control over the obedient populace. It's no wonder sexual fantasy is the easiest target for thoughtcrime - so much of it involves exploring (and enjoying) the breaking of rules and taboos. Sexual liberation is freedom from tyranny.
I would rather a man indulge his craving for despotism in the realm of sexual roleplay (with an emphasis on the word play), than to repress his sexual urges and become a despot in the public and political arena.