I don't either, but I would also like to refute the idea that blank slate characters are lesser characters. They just serve a different purpose. Some, like Ness or Steve, are your anchor to the world; The eyes you see it through. Others, like a lot of MMO avatars, are pure wish fulfillment, and they exist to allow you to live out your fantasies of being powerful adventurers that save the world every Tuesday. Others still are just as explored as characters as any other. For example, Lucas never speaks, but the events that happen through the story and the way that characters talk to/about him show you the struggles of the character, and who they became as they overcame them.
Of course, all of these can be done poorly, but the ones that are done well should get credit where credit is due. And please note, I'm not expecting people to like blank slate characters either, just acknowledge their merits. I mean, who's to say a multifaceted character who is the center of an 11/10 plot with riveting twists and turns is any better than a childlike, vaguely human character who allows you to roam a planetoid that you get to shape to your liking, chill with the humanoid animals that live on it, and relax. They're apples and oranges really.