The reason the ones without flanges do that is because of the fact that female orangutans are generally attracted to the flanges. So, basically, females would not be attracted to ones without flanges; The ones without are incels, you could say. That is why they may rape females.
And I don’t understand how that makes them “bad” persay. They are only trying to sastify their high libido.
And look, I do not support rape at all. But, it’s kinda weird to call a non-human animal “bad” for following what is basically their instincts. Yes I know you clarified that they are just animals, but it still doesn’t make sense to call them “bad” in the first place. I’m not trying to be mean at all, I just want to know if you really do think that they are “bad”.
If I have misunderstood you, then I do apologize about that.