This is truer than ever. There is one in particular that has plastered his ugly mugshot in his avatar and things everyone wants to look at his ugly bottom, err sorry, face.
I think avatars make the overall website look better as they're used in a lot more places, not just in threads. That's the only reason why I have one - for ages I had no avatar.
Though I would agree that annoying/tasteless avatars should be forbidden. A lot of websites explicitly ban all animated avatars, just by not allowing .gif filetypes,