Clock said this same thing and I ask why is there a protagonist at all if you aren't going to write him or her? And self awareness regarding a character's parodic personality doesn't excuse bad writing. See: every movie with a Yoda knockoff that acknowledges that the character is a yoda knockoff. I submit that if killy were a mute or if blame were a video game with him as a silent protagonist I would have enjoyed it considerably more.
Was it a masterpeice of characterisation? Nope. Those few characters who survive past two books have already done their emmotional development. But that pretty clearly wasn't what N-boy was trying to do. So I'd still call it a success.