Agreed but I think you are mistaking the two items. Pow board doesnt equal free ride board. Just like jib board doesnt equal big jumps. Even though they are in the same area of riding the design of them is slightly different. I ride an undisputed as my pow board and it works well for me, but it isnt classified as a pow board it is a freeride board. It is stiff and i can go off cliffs and bid drops with it. That doesnt mean I would take a pow board off of the same stuff.
Most people use powder boards on fairly mellow terrain since most people ride mellow terrain in general, when riding mellow terrain float is the most important feature on a pow board, once the terrain gets steep you are going to float on anything and the shape of a pow board becomes less important.