Better acting and script quality is not an inherently western construct. Like someone else said, years ago, a character like Yuffie was more tolerable because FF wasn't voiced. Now that it's voiced people, while going up against the other heavy hitters of the year people are expecting more.
Not only that, but those old characters also barely had any actual animations when speaking. There's nothing in FF7 that shows Yuffie acting like this XV girl.
Of course, she will in the Remake, because every character needs to fill the usual anime archetypes.