Earlier quoted context omitted.
That was my first idea too! Not that people suck (not sure why you must suck if you enjoy looking at good-looking people), but that it's organic. Instagram just prioritizes what people click on, and people are attracted to attractive people, so they click on that.
Follow-up questions: - Does Instagram prioritize scantily-clad photos of attractive people over scantily-clad photos of relatively less-attractive people? - Is the prioritization based on a machine analysis of the photo, or on the response of earlier users to the photo? - "While [the skew towards nudity] was consistent and apparent for most volunteers, a small minority were served posts that better reflected the dive…
I would bet the latter. Why go to the trouble of analysing difficult stuff about body structure, when you can just let users "decide".
I think we should formulate a law, something like "every internet imageboard, if left to user-moderation, will eventually turn into pr0n".