But even when Dragonite did not listen to Iris she was still winning battles with it left and right and I think that was what annoyed some people because it sent a bad message that you could still win alot even if your Pokemon doesn't like you.
And to make matters worse, it actually started losing once it started listening to Iris. I think the first battle where Dragonite listened to her was her battle against Ash, where he and his mid-battle evolved Krookodile beat her Dragonite. And things only went downhill from there for her Dragonite.