Nothing really prohibits it but if you are fly fishing then you only have a couple of spots where you can cast effectively. And then you have multiple current seams that you are trying to deal with. It's not easy to get a decent drift through there.
I only fish that area during the winter and usually have a buddy with me that doesn't wade and uses spinning gear. He spends most of his time watching me catch fish from the shore. I'm not saying that he never catches any because we both usually leave with a limit, but I catch a bunch more. If he would wade though I'm certain that it would be very even.