Why was the ps vita not called PSP2?

[VAMatt]

In hindsight, we can see that the marketing department screwed up by bringing in the new name. But, at the time, I'm sure they were thinking that they want people to consider it more than just another gaming system. PSP2 would have clearly just been another gaming device. Now that we see poor sales of Vita, that's clearly idiotic. But, they didn't know it was gonna sell like crap at the time.