Well they did yuffie, in Advent children, and Dirge of Cerberus. So you can see for yourself what she would have sounded like.
I think it depends on your perspective. For instance, Barrett is an extremely stereotypical character, yet your imagination might have made that funny. But if you heard it. He'd be just completely offensive to a lot of people. (and you can here him in AC, and Dirge).
Now you can argue that this is better, but I'd argue that it's still bad, except some peoples mind is convincing them otherwise.
FFX though I loved the story, had good voice acting for it's time, but bad compared to any of it's successors imo FFX-2, 12, 13, and 13-2 were all way better voice acting wise. So it's hard to blame voice acting, when a game without good voice acting did it successfully atleast form your perspective.
Story Games I love this gen, Bioshock (voice), TWEWY (No Voice), Deus Ex HR (Voice), Crisis Core (Voice), Peace Walker (Voice), Mass Effect 2(Voice) <-- though the story isn't that great, the characters are though so...
Most of these I'd put against my favorite story in any gen. But then again. I don't hold older stories in as high as regard as some do. My favorite videogame storys generally get trounced by my favorite movie or anime story by a pretty hefty amount.
I think too often, developers try to make videogames feel too much like a movie like MGS4, for instance, FFXIII not that I didn't enjoy those games, I did. FFXIII-2's approach I like a whole lot so far. Uncharted's whole concept is that so that's why it works there for the most part.
