You can't say "they don't have a story because they don't need one." That's not really an answer. There are plenty of things which we don't need in life which we have anyway.
And you can't say it's because a story wouldn't be appropriate for porn, either, because obviously it is: just look at all the eromanga and doujinshi which tell stories.
Granted, most stories in porn are pretty poor, and even the best stories wouldn't come close to making the grade for reading lists' Top 100, but I still would like to know why it's relatively easy to find a good erotic story accompanying good erotic artwork in hentai but you never find a good erotic story accompanying good erotic camerawork + human specimens in JAV.
And you can't say it's because a story wouldn't be appropriate for porn, either, because obviously it is: just look at all the eromanga and doujinshi which tell stories.
Granted, most stories in porn are pretty poor, and even the best stories wouldn't come close to making the grade for reading lists' Top 100, but I still would like to know why it's relatively easy to find a good erotic story accompanying good erotic artwork in hentai but you never find a good erotic story accompanying good erotic camerawork + human specimens in JAV.