Let's deal with the characters first. Clichéd? Perhaps. They do fit into some archetypes. But then, they're meant to. The point is to have a group of people working together who complement and clash with each other. But they're not 2D carbon copies of archetypes either. Tidus is a whiny douchebag? Okay, but he's also got severe childhood issues with his father and mother. Plus, he stands up to everything when he decides that the woman he loves isn't going to die. What about Tidus being the egomaniac sports star? Again, he's got a bunch of insecurities because he's always living in his father's shadow. Then he gets transported to a completely different world and is still living in his father's shadow, only this time his father is a giant smurfing whale monster who is hell bent on destroying everything. Then he has to come to terms with his own mortality, a complete existential crisis because he's not even real and does it all while still maintaining his flaws; that is, he's still a fish out of water and completely clueless on how to act in Spira.
I don't doubt that a lot of Final Fantasy X's ideas are intentional. But intentional does not equal well-executed.

I never doubted Tidus' situation with his father and his home being genuine, I never doubted that his reaction was deserved. My issue is that it was handled with all the subtlety of a nuclear bomb. Tidus dislikes his father, yes, but this is rarely explained in ways other than him talking about constantly.

I understand it's an important aspect of the plot, but they really should have used a "show, don't tell" storytelling mechanic. Tidus really only has one method of displaying his dislike for the guy: talking about it. And while I can understand the need for such dialogue, going through 40 hours of less-than-stellar voicing about his poor relationship with his father eventually gets a bit tiring.

And again, I realize Tidus' situation in being an unfamiliar world is significant as well. But again, this is handled with little subtlety. He blatantly disrespects people's beliefs and customs from the get-go (and even as wrong as they are, he had no reason to believe this at that point). I realize he wants to go home and doesn't fit in, but after 40 hours of him speaking about this it eventually loses its sympathy.

In short: Tidus as a character isn't a problem, it's the lack of subtlety in the writing that causes him to be unappealing as his desires and insecurities either become a topic of long conversation or handled in a way in which his motives are not well-defined. I think the character's struggles should have been weaved in to the story more through his unspoken reactions and hints rather than multiple speeches.