"To thine own self be true...."
Personally, I like the rules as stated. This is because they align closely with "my" version of this "fantasy". I'm a bit of a control freak and the fact that she/he must enjoy it gives me that level of control over said villain as I place myself in character. It also distances me even further from the actual reality of the situation (which is what fantasy is all about after all...unrealistic...not realized...not actually happening, etc.,etc...).
Now those who would write it in spite of the stated rules and enjoy the total domination factor sans character enjoyment...well, that's their preference. I don't judge, it is "their" fantasy. So I say live and let live...