Just to refer back up to the above:
This is a really good video, and it really delves into how the are hardcodes tendencies in what men and women find sexually stimulating. One of the biggest things to realize is that men can and do get erotically charged by a single sexual cue, so that a nice pair of boobs or a nice muscled chest (depending on if you are gay or straight) is enough to get people going. It is, and I've seen this confirmed in other stuff I've read, a tendency towards objectification in sexuality, a focus on very specific visual cues absent of context (like the rest of the person).
When you consider that paraphilic obsessions are usually centered around very specific visual, or sensory cues, then it makes perfect sense that men would be the sex to develop these obsessions. But I think the focus on futanari to explain AGP is wrong. There's a thematic link, but when you listen to AGPs, the specific visual focus that so so many of them obsess over is specifically the "smoothness" and "flatness" of the genital area. Hell, we had an AGP video in this thread where the dude talked about how his obsession started with aerobics videos, because of the women in leotards. It's a recurring theme, over and over, the specific absence of a genital bulge that gets these dudes off. Beyond just porn, I think media stimulus in general, especially sexually suggestive stimulus around the age of puberty, probably triggers this sort of obsession in a certain subset of straight men predisposed to more extreme paraphilic obsessions (since there does seem to be proof that paraphilias, or the tendency to develop them, is somewhat hereditary). This is where you see that some AGPs focus on swishy sundresses, on spinny skirts, etc. It's all the very specific, reoccurring visual images that you are repeatedly exposed to through media, that are visually linked to the opposite sex.
I've been wondering for some time if the ubiquity of just visual stimulus, the ability of screens to just stream information to a brain, might be the thing that fucks people up. It's very different from anything humans prior to even the 1950s experienced in terms of the sheer amount of visual stimulus we receive.
There were those studies that showed that people who were exposed to grayscale media were much more likely to experience dreams in greyscale., so it seems plausible to me that the human brain just wasn't built to process visual stimulus out of context of the immediate environment. It may be that we are still not realizing the degree to which screen exposure of kids is messing them up.