An adult female and an adult male having a consensual relations is related to 'rights' in what way exactly?
Because I don't think that has anything to do with the situation.
Exploitative by whom? Students don't have to f** profs, it's never been that way.
Your posture is actually sexist, implying that somehow adult females cannot make their own choices.
Unless they do or feel like they have to. That's the whole point, when there's a serious power imbalance like teacher - student, boss - direct report, consent is not so easy. The person with less power can have their life/career/studies depend on the more powerful one, and they can feel that they have to fuck them, or continue fucking them, or do that kinky thing they don't feel comfortable with, or else, even if that's not the case (but it sometimes is). That's why many places have strict policies that forbid such relationships, and it's up to the professor to know better even if they both want to.