A lot of good points here, its sort of like the music industry knowing what the majority of people with their own money want to hear. Problem with porn is, cater to everyones' particular desire and you create a million niche markets
I can still remember 10 years ago when I worked in a video store. Edward Penishands was a popular rental. They actually attached latex dildos to a guy's hands and and it was an attempt at a serious storyline. How all the women in the movie wouldn't stop the shoot with constant laughing is a mystery, but I bet the gag reel (no pun intended) is filled with crack ups.