a) It implies that there is something wrong with nudity, sexuality, etc... which is wrong, the idea alone is repressive
No it doesn't.
It only acknowledges that there are things that some people like, and others don't, and funnily enough, that's a good thing, and it's okay. People are allowed to like different things, and if those things are easy enough to filter then it should not be used to exclude them from a greater body of content that they would otherwise enjoy alongside the people who also enjoy the bits they don't.
b) If companies would stop catering to the people who think that nudity, sexuality, etc... is wrong then it would create a new climate in society and establish new facts - streaming platforms, etc... simply couldn't afford the anti-sex agenda anymore
Forcing everyone to live the way that you think they should, and not providing them options to do otherwise, is, by actual definition, Oppression.
Don't get me wrong, I'm an extremely sex-positive person, and I enjoy adult content in my entertainment media even if it is not the subject or focus of it. I'd even like and appreciate more such things, and a more relaxed approach to it in all walks of life, as long as it comes alongside better education, awareness and good mental/emotional health practices. I disagree very strongly with enforced censorship in ALL its forms.
However... if I start trying to demand that people not have the option of opting out of those elements that they don't want to engage in, while still experiencing the rest of the material, then I'd be acting directly against that exact philosophy, and doing exactly what it was I was pushing for others not to do.
(If you look elsewhere on these forums you'll see that I'm pretty in favour of the open-minded approach to the presence of adult content in these games, and I want to see it done well... but if I say that people shouldn't have the option of telling the game to black fade those bits for them, because that's what they prefer, then I'm just as bad as the people demanding that the scenes shouldn't exist - exactly as bad, in fact.)