I don't think anyone is saying there is a "need" for any kind of pictures for avatars.
But you can easily identify posters through their names. Generally speaking (despite the recent amount of changes)..the names stay the same and the avatars change.
I'm speaking from someone that doesn't turn them on at all, and I don't have a hard time browsing threads or identifying posters. But, just like any poster that you can put on ignore, you DO have the option of turning them off at work if they aren't appropriate.
I didn't realize people were/are so tied to these avatars instead of the name of the person posting.