I think SE made a big mistake trying to sell Tetra Master as a stand-alone game. It wasn't strong enough on its own to make it, and it would have been so much better if it were included into FFXI as a minigame to pass the time.

Think about it, you have a game where cooperation with a party for a lot of the content is key, but no everyone's schedules are the same, so now and then you find yourself having to wait for a long time. If you and maybe a couple of friends are going to be waiting for a while, why not pass the time by sitting down and playing a hand or two of cards?

It doesn't even have to be Tetra Master. You could make a completely different game, or you could dust off Triple Triad if you really wanted. (I'd probably never play it, though, because Triple Triad was too random. I get enough RNG bull-crap with boss battles.)