I think this argument is completely spurious, but it does add an interesting additional dimension to the debate. I personally am not excited by torture, though I am quite excited by fighting - a practice which is almost as destructive and negative. Many fanfiction writers do put scenes of torture and suffering into their work, as do professional writers of all genres. It can be hard to read, but it can also enhance the work - often both things are true.
I think there is a difference between being excited (or otherwise positive) about the representation of violence, and wishing to promote violence in real life. My guess is that people who are clear to themselves about what they are excited by are more able to keep a distance between their own shady desires and destructive actions in real life. Being clear that I like films where men fight each other, I think I am less likely to cheer on a war.
In contrast I suspect that some people who advocate war, torture, the death penalty etc. do so for sexual reasons which they have repressed quite tightly.
Having said all that I think that I would be wary of trusting a guy who said he was excited by thoughts of dismembering women. I know I contradict myself.