I could make a large laundry list, but it's porn -- taking it seriously is a mistake. Three things come immediately to mind:
- The camera work is uniformly terrible. I saw a scene recently in which the camera person was focused in a pillar, while the performers were off to the side. It was insane. And then there are the guys who cannot keep the camera still for more than five seconds. I'm sure there are a lot of reasons for this (gonzo being the dominant genre is one of them, I'm sure), but it's distracting.
- The "porn missionary position." It's not that often that you see the simple missionary position in porn. The girl has to turned to one side to make absolutely, 100% sure that we know the guy's fucking her. It's insulting, at least to me.
The reason for this, I imagine, is because you can't actually see the male talent's cock clearly at work in conventional missionary. James Deen and Dana Vespoli made fun of this a while back in one of their scenes when Deen stopped while in the midst of doing it to show everyone that yes, he was actually fucking Dana and not faking it. It was funny at the time, but the more I thought about it, the more annoying it was. Good camera work would fix that problem -- I've seen it done well.
- The sometimes creepy age difference between male and female performers. Watching some 18-20 year old girl bang a guy clearly old enough to be her dad weirds me out. It's why I avoid schoolgirl or babysitter scenes like the plague. I know that it floats some people's boats. Just doesn't float mine.