I am aware of instances of fit people being convicted of these sorts of crimes, but mostly when the victim is very young. When the perpetrator is attractive the victim is much more likely to feel like they really wanted it (whether that is a real desire doesn’t matter as far as their reactions go) and the victim often declines to cooperate with an investigation.  Also, fit people have better self control so they  don’t act on their illegal desires and have good enough judgment not to get prosecuted if they do.