Why did people apparently dislike Yukari? Is she different in P3R or am I missing something?

For context, I haven't finished the game yet, I'm only in mid-July. But I remember hearing that people actively disliked Yukari for some reason and I just... don't really see why? She's not perfect but she does her best, apologizes for her mistakes, and generally tries to do what she thinks is right. Does am I missing something, or was she just not as well received before?