I only care about the images and not the interaction so much, so like having non-anonymous boards in there. The default settings already keep them hidden (well there is only one example to hide so far), since I know others feel differently.
If everyone I talk to complains, then I might start calling non-anonymous ones galleries and stick them in a 'didn't quite make it' listing. But then what would 5chan have rated as? It's weird calling it a gallery when it was users posting the images and users commenting on them.
Forcing all image boards to be anonymous might be just like using -chan for site names all the time. Something we're taking from the Japanese and not deciding ourselves. Maybe those furry boards that everyone hates could cut down on the trolling they get if they required sign up, for example, and that would outweigh the benefits of allowing anon.