So, right off the bat, your comment does nothing to address the fact that having AI porn available means that young children will be exposed to it, and teenagers will be watching it while their sexuality is still forming, and it will have a detrimental effect on them. It conditions them to want what they see on screen, or find it arousing, and the fact that it's not real people doing it doesn't change that - if anything, it could result in them wanting to do even more unrealistic things, as the AI isn't constrained by human biology.
It also doesn't address the fact that porn viewing generally results in escalation - studies have shown that humans, on a demographic scale, become desensitised to what they began watching, and begin seeking ever more extreme pornography to scratch the same itch.
It also doesn't acknowledge that while only positive, non-harmful, collaborative sex could be shown in AI form, that is not what actually happens, and pornography isn't restricted to that for the aforementioned reasons. In fact, I disagree that most porn presents non-harmful, non-painful sex - most porn, even 'vanilla' porn, involves choking on penises, rough handling, a lack of proper behaviour around consent, and the infliction of discomfort if not outright pain, as well as submission on the part of one participant (the female one, in hetero porn).
Additionally, people are not cementing 'murder is good' in their minds while watching films by masturbating to it. Orgasm is a very powerful conditioning tool, and if people were masturbating and achieving orgasm while watching people being 'murdered' in films, I would be very concerned, yes.
I'm curious - do you think that pornographic material depicting children is 'fine' if the content is AI made?
"I also think a lot of women just don't like seeing the less palatable aspect of male sexuality laid bare for what they are." What do you mean by this? I think women are generally extremely aware of the ways in which male sexual behaviour can be harmful, never mind porn.