Wii U is the dominant version of CoD, that's why. If sales would pick up, and if we got DLC, this would by far be the best option. We have 2 unique features you do not.
On another note, I will be buying ghosts on Wii U. DLC doesn't matter to me. I encourage you to everyone else to buy it also, simply to show support. It does seem to have some notable improvements.