I also disagree with this common notion, although I think a whole new thread could be opened on this topic. As unpopular as it is to say I do not think that ALL rape is about power and think sometimes does have to do with sex, otherwise "date rape" would never happen. The issue also gets muddied because the cause for anger towards women and the need to take power could easily spawn from not being fulfilled sexually.
I also don't understand why people don't think rape could have more than one cause depending on the individual rapist, the same way murder can. I'm pretty sure Jeffry Dolmer, Jim Jones, and Lee Harvey Oswald all had very different reasons for the murders they committed, why would rape not be similar?