agreed, and it's frustrating that these terms are used the way they are on here because in IRL communities with more experienced kinksters & better kink education, CNC is a wide umbrella term that encompasses many things, including but not limited to rapeplay. CNC is when someone consents to something that they either genuinely don't want or will pretend not to want by verbally/physically protesting.
"but if they genuinely don't want it, isn't it an actual consent violation—" not if they consent to it! for a lot of people, part of BDSM is being pushed beyond their comfort within pre-negotiated boundaries. (pre-negotiation is key here—obviously care must be taken to avoid crossing into coercion, but that's another conversation.)
"then how can you have CNC that's not rapeplay?" much like that "is kink always sexual?" poll debate, this is a confusion borne from the general misunderstanding of kink on this site. you can have CNC that's not rapeplay because kink does not always involve sex.
for example, you can consent to any of these: being spanked while you're crying and screaming. being held down and tickled as you genuinely try your hardest to get away. doing something that sensorily disgusts you. a kink educator i took a class from recounted a CNC scene where she was tied up and forced to eat her most-hated food.
forced orgasms and post-orgasm torture (and other kinds of overstim) fall under CNC and could be called rapeplay, because you can withdraw consent at any time, so touching someone beyond that would be sexual assault. somno and intox are particularly risky types of play because you legally cannot consent while asleep or intoxicated, whether you previously established consent or not. whether your personal definitions of rape and SA agree with the legal definitions in your area is up to you, but they're good to keep in mind nonetheless.
(editing to add: a huge part of what makes all of the above examples consensual is that you can safeword at any time!!)
how you personally choose to classify different acts in your own play (as rapeplay, CNC, neither, both) is your choice, but it's not immune to criticism, and it has the potential to reveal subconscious biases. every method of categorization is by nature imperfect, so it's not necessarily wrong to have a distinction in YOUR mind between rapeplay and overstim, for example. but as OP said, the problem is when you're arguing that these distinctions are universal and absolute, and making moral judgements about others based on YOUR personal, imperfect categories.
