How? Lets say for example you draw a couple engaging in regular sex, how does this promote exploitation or reducing people to objects?
If a persons takeaway from drawn or written porn depicting nothing more then regular sexual encounters is that the subjects in it are nothing more then objects, that seems to speak more about the viewer then the medium.
That's like the "Video games cause violence" narrative. If you cannot detract fiction from reality, that is an issue with the viewer.
Do you see two people engaging in an in-person sexual-attraction based hookup as exploitation?