Then you misunderstood the entire game. :P
The point of FFX was character growth. While Tidus starts off as a whiny little bitch who wants everything to go his way and handed to him on a silver platter, he eventually becomes a passionate man who isn't scared of causing his own non existence to end a worldwide threat. You see the same with Jecht's memory spheres in the game. The game is all about self sacrifice and rising above one's own petty beliefs and desires for the greater good. He doesn't get rewarded at the end of the game, he doesn't get to live on and see what he accomplished, he is forever doomed to be just a memory, remembered by only a handful of people - and he's okay with that.
X-2 on the other hand, just says fuck all that, he should be brought back for a happy reunion ending. What a disappointment,