It was in a holiday bundle, you realize the concept of a bundle covers individual sales as well? Point being, when the few people who purchased a Vita last holiday got one, they got the Call of Duty bundle. And it had nothing to do with what the system was designed for, but the Call of Duty name.
And regardless of all this, the COD Vita argument ever since Vita and even 3DS launched was always, "well just wait for Call of Duty Vita, everyone will be buying it in droves and will put Vita up there with 3DS." It wasn't that Call of Duty would sell well for Vita. It was that the game would push Vita to at least be a player in the handheld race. This was repeated and believed by some again and again. It didn't Sony revised their projections down three or more times during the timeframe and 3DS crushed it. It was a complete and total non factor.
If the Call of Duty brand with a bundle isn't going to do anything, your system is dead.