You don't like Mai? Fine, whatever. But no reason to go mean on the character. Especially because:
1) Zuko's a dweeb. A hothead. Until recently an ungrateful brat too who tends to be over dramatic, too busy to listen to what uncle Iroh had to say, and was begging to get his butt kicked. How is he so "high and mighty" from Mai? Now, don't get me wrong, the guy has his good point, but also does Mai. Mai has sarcastic wit, is talented, she is calm and collected, poetic, and knows how to move in life. I seriously think that Mai can read Azula perfectly and keep up with her.
2) If you ask me Zuko needed more than one slap. And that's before the CoD thing. That doesn't devaluated him as a character. It actually adds because you want them to snap out of it so they can grow.
3) Mai's not ugly!! She's not your type? Fine! But dammit, she's not ugly. Aside from the "old ladies" and poor Meng (I think she's just on an awkward stage) avatar has no really ugly girls. They all have something unique to them. Mai's tall, slender, has my favorite pair of eyes, and her hair! Dude women pay hundreds for the hair that Mai has. Also I love her outfit for some reason. XD
Seriously, this is why I hated the Inuyasha fanbase. This Mai bashing reminded me of the Kikyo bashing. Which was ironic because Kikyo's pretty much Sessoumaru without a dick.