I guess a lot of the party members do annoying things... I was having trouble remembering what Aeris did, but it was the series of preventable events that let up to those spoilers.
i used to think it made me kind of a misogynist that i found all of the female party members (plus cait sith) to be pretty annoying, but then i realized it was just lol japan/lol square writing.
i probably liked aeris best at first.