I’ve encountered people constantly assuming sex is good and that having sex is just something you do in healthy relationships. This creates a situation where, hating sex is a character flaw caused by those terrible sex-negative tropes society presses on you, and obviously only Bad People don’t consent to sex.
That’s rape culture. This is what environments that assume sex is unambiguously a good thing do. Saying, “It’s consensual sex that’s good” doesn’t actually fix the problem. It just creates a situation where you must be consenting to sex, because if you aren’t, you’re not having enough sex and then you’re “sex-negative”.
See, it only fixes a problem where you’re like, “Well I don’t really want to do this right now”. It does not do anything at all to help people who find sex painful. It does nothing at all to help a person who doesn’t want sex, but thinks they do because it’s been so heavily normativized they have to have sex, and have to have it in this specific way. All the, “But make sure it’s consensual!” thing does is tells the person, “Well maybe if you don’t want sex this time it’s okay, but remember you still must be having it some of the time!”
See, to actually fight rape culture you need to say “Sex is always optional. You are never obligated to have sex.” You must always be concerned with consent, and that means you must accept that the answer may very well always be no, despite the fact there’s this belief sex is the greatest thing ever.
And if someone never wants sex, then sex can’t really be a good thing to them, because it’s always unwanted.