I agree with the poster who said this is basically Spoony's review in essay format. At very least though your review is actually a credible review. Spoony had points but decided to shout and rant and rave instead of presenting anything logically, so your review wins a 1up shroom. I disagree with a lot of the points though. No time to sort through them all, but let's tackle the major ones:
Characters: I won't go through them all, but let's just stick with Tidus. I don't understand the hate he gets because he's not a stoic super soldier like Cloud or Squall. In contrast, like Zidane he behaves in a manner that is incredibly believable in relation to the real world, especially considering his backstory. He's a sports god that suddenly is on an escort mission of the one woman who can save the world. Of course he cried about it at first. However, by the end he's staring his doom straight in the face, and he makes the right decision anyway. He traded his life for the woman he loved essentially. I don't see how that's a weak characterization, because his growth was steady and never really that jarring in my opinion. His major problem was...
Voice Acting: Yeah... it was bad. However, it was the first time the franchise had tackled voice acting. While a few games had done it incredibly well such as Soul Reaver (still one of the best), it was still a relatively new thing. Besides, back when it came out I and many others thought the voice acting was good with a few exceptions (you know which scene). It was a problem, but... eh.
Exploration: Technical trade-off. They ditched the overworld map, but it finally allowed them to have a fully rendered 3D map in real time. That was HUGE, especially considering how long the game is. However, they did make up for it in a lot of ways. The major mini-game soaks up many hours, getting the ultimate weapons requires a lot of roaming off the beaten path, and the creature arena provides plenty to do. Not the best trade-offs in the world, but honestly I found the extra exploration in the playstation era games alienating at best and frustrating at worst.
Plot: What of it doesn't make sense to you? It starts as a rather cliche journey of a woman who is destined to save the world, then it slowly unravels the layers and brings the cold, ugly truth out into the light. If you're saying it doesn't make sense when all pieces are brought together, then I guess I can break it down for you.
Many games bear the name Final Fantasy, but this one is probably the only one where the name actually serves the plot. The people of Zanarkand wanted a chance for their home to live on, even if it was merely a dream. They recreated it and had sin as the protector of their Final Fantasy (ZING!) Sin went rampage trying to protect it though, and then you have the events of the game. I don't see how this plot is nonsensical or convoluted compared to say... VII. At least in this game you don't have 3 different accounts of what the hell is going on.
Did this game ruin the series? I don't think so. The next single player title in the series was XII for goodness sake. There is no numbered Final Fantasy that is anything like XII, as the only games it bears resemblance to are games in the Tactics series. It had unbelievably good voice acting, great dialogue, the writing was solid, and the plot had intrigue for both the advancement of the story and the believability of the characters and especially the villains. Then of course you have XIII. Something you have to remember about XIII is that after XII, many fans jumped on the hate bandwagon and destroyed the game on message boards across the internet and clamored for the formula of X. And that's pretty much exactly what they tried... though in my opinion they failed miserably.
If you hated the change of formula in XII and the unfortunate return to form in XIII, it might seem like the series has gone downhill. However to me it just seemed like an experiment followed by a return to form. Both of them were received quite well critically, but fans are divided. I think it will take one more major title to see whether or not they've lost their chops.
