Monster Hunter and Resident Evil are firmly established on the 3DS.
Theatrhyhtm and Bravely Default indicate that Square Enix will support the 3DS at least as much as a FFX port suggests they'll support the Vita.
There is no reason to believe Call of Duty will be as big on the Vita as on the 360, especially when the PC and Wii incarnations of the game do modestly in comparison.
Gran Turismo was not that big a hit on the PSP, and there is little reason to believe a Vita version will do much better. And the game hasn't even been announced yet, so that will be late in the Vita's life.
Fifa was never that big on the PSP. Once again, why would things change?
The early reports of the 3DS causing headaches disappeared when people actually started playing the system. .
Games like Resident Evil: Revelations prove the 3DS has graphics comfortably ahead of what 7th gen handhelds can offer.
Vita ports are possible now. But what about in two years, when the consoles are all replaced? Suddenly, ports aren't very easy anymore.
Nintendo has done alright with new IPs on the 3DS. Pushmo was a major hit, and games like Steel Diver, Rolling Western, and Kid Icarus prove that they're willing to go in relatively new directions.
In short, I think you're completely wrong and your reasoning is unsound.
But it's nice to see you.