>>1248278pretty rare to find that kind of porn. Think it just generally doesn't look good on camera, unless you have a super aggressive top. And theres so few positions that actually work out and even then your faces rarely line up so hes just staring at your back or something.
I find even in my own sex life I usually end up topping even though i prefer to bottom. Guess its just easier, like every position you line up perfectly with a bigger top and smaller bottom. Dated a "top only" guy and by the end of our relationship he was bottoming more often than not.