Well, it seems like a lot of people would like their avatar to look different from the others. Why would it have to be through character creation only ? I think you're simply seeing the MMORPG in the strict sense, and that's being narrow-minded.
And besides, it can be taken as a form of Role Play (changing clothes following your mood).
And if you don't like it but other people would like to have it, why wouldn't you just not use it ?
