Consenting adults should be able to do whatever they'd like with each other and if they want to record it and share it, that's none of my business. How much mainstream entertainment is centered on murder? Is that ok?
The moral argument however is worth considering. Numerous well cited studies have discussed the deliterious effects of porn consumption. Porn (over)consumption directly correlates to loneliness, especially among males, for example. It also correlates to poorer relationship outcomes, increases in the rate of STDs, and other interpersonal issues. In general, porn is no different than any other drug with all the downsides associated.
We cannot say the same for "mainstream entertainment centered on murder". Murder in general has trended down year over year since the 60s. One would be able to make a stronger counter argument: the exposure to violent media has possibly made violence less appealing. You are bordering on using "violent video games create violent people" as proof we should not view porn differently. These are not the same argument as shown by a trivial search of elsevier.
Nah, actually I did read it but I disagree. I don't want people imposing their morals on me. Adults are responsible for their actions