Very rarely does anyone actually point out a specific problem they can put their finger on, it’s always just “Bad UI /grumble mutter/”.
I don’t think there’s too much actually wrong with the gaim UI; personally. There’s a few menu options in all the wrong places, but that’s about it.
Don’t think I’m right? Got specific problems. Stuff that makes gaim unusable for you? Tell me about it and make me eat my words.