I completely agree that a card game should be added to the game and that it should really be IN the game and not like it was in XI. I don't think that excludes an app or something that makes it possible to play outside of the game as well.
Out of curiousity though, why Triple Triad instead of Tetra Master?
For those who don't remember here is a small comparison of the two: http://www.ign.com/blogs/godofmoogles/2012/01/25/final-fantasy-celebration-card-game-showdown-triple-triad-vs-tetra-master
Personally I could see the card mod ability being used for XIV depending on what items it could yield, but that could be used even if XIV had Tetra Master. Personally I want Tetra Master more than Triple Triad, more complexity and depth is a good thing imo, as long as the basics are easy enough to get everyone involved.
Either way though a card game seems to be the most wanted minigame for XIV overall, and I really hope Yoshi listens and adds it.