I feel like you're taking a joke way too seriously. But nonetheless, I'll humor you. What you're saying isn't wrong, and in fact that's how it works in the first game. However, [stated] does not equate to [actually seen in game].
In the first game, when you accumulate large amounts of corruption, you can actually see that reflected in gameplay. Companions leave you unless they themselves succumb to your corruption, you can no longer use certain weapons, your libido is through the roof, most non-corrupted NPCs will avoid you or attack you, etc. On top of that, the setting of an already corrupted demonic realm makes the whole 'rape upon loss' mechanic work well since that kind of depravity is to be expected.
In CoC2? You barely, if ever see much what corruption actually does to someone aside from the Alraune, Centaur Village and the Bee Hive. For the most part, getting raped upon losing is less because your enemy is corrupted but more because that's just how it is. And before you say it's consensual, because lord knows anything's consensual with Cait, last I checked, the player never had an option to decline getting railed in the ass upon losing. Most of these enemies that rape you, barring the demons themselves, are usually not corrupted.
I bring this up since you specifically bring up how corruption makes people being okay with raping others. If most of the mobs that are not corrupted rape you anyway, the only real difference corruption makes is simply how you look. I understand that the lore makes it very clear what Kas' intentions are and what corruption does to a person. But, to me, all of that falls apart when what I see and experience in game differs heavily from what the game wants me to believe.
Lastly, in case you haven't caught on by now, questioning whether demons are bad are a joke. But is Kas really the villain?