Honestly, Tidus doesn't whine any more than Cloud or Squall did. Everyone just noticed it more because Tidus was the first one to have a voice.

And really, Tidus is a guy who went from a life of luxury and fame in a glamorous shiny world into a foreign, destroyed world riddled with constant dangers and death, not knowing what the hells going on, and only ends up figuring out negatives about his existence (or lack thereof, rather).

Who wouldn't be more than a tad whiny in his position? I know I would.

That being said, Final Fantasy X completely blew me away the first time I played it, and I've replayed it several times since, and just started a new game last night, and am once again loving it. It's one of my favorite games of all time. I just love the story, the characters, the level up system, the battle system, the summons, the soundtrack, the scenery, and many of the boss fights are some of the most memorable in the series, for me. It's probably the closest thing to a perfect game I've ever played.