To be fair, I'm certain that the people who wrote out Tidus' character were experienced, too. Sometimes people just view characters differently - it can't be helped. A great example of this (for me) is Cloud - I don't know if you've seen the two different poses that Nomura drew him in, but they show a remarkably different personality. Then you have his Advent Children character, which is different again. His Crisis Core character, again, different. It annoys me to no end that they mess about with his character so much. Still, I've always seen him as I did the first time I saw him - a strong character in body and mind. Even when he was struggling with his inner demons, I saw his strengths shining through. I just can't do that with Tidus - my first impressions of Tidus were that of a bleach-blonde surfer moron who likes to complain and I guess the saying rings true that first impressions last. I liked to use him in battle, though, and he didn't annoy me 100% of the time. Just... most of the time that he talked or interacted with anyone.