Well, first of all, it shows all of our bits and pieces- and all the worst parts (stomach/boobs). To be in this position, you have to be comfortable with your body-- especially if you are going to be in reverse cowgirl where they will see nothing but your ass. Furthermore, there's the question of an awkward puzzle situation. If the guy has really wide hips, sometimes it's difficult to spread your legs wide enough to be on top. And finally, there is a lot of pressure to perform. Sometimes, the dick is too big and it hurts to go all the way down on it. Sometimes it's too small and there's awkward smashing down to try to get it to feel good for everyone. I'm not bashing the position because I love it, but just bringing up some points about why it not be the best idea to do when hooking up for the first time.