I agree with what WV posted and those are my thoughts on it as well.
As the Dom, giver... I would not wish to give what isn't wanted... if there is no pleasure from it -- how do I justify my own pleasure? Guess that requires more of a Sadist than I am.
As the Dom, taker .. I find there is pleasure in watching her receive and perform tasks... again any consequential pain is wanted. The whole session of D/s is what I'm after.
Pain is a result .. a by product of the things we ( WV and I ) do.
It is not a goal or a requirement of our sessions.