I must disagree with you about the matter of his ability to hold an intelligent conversation. Sure, a younger brain is less developed and usually you have less insight at younger ages (hell, I often look back at the things I've said five years ago and facepalm), but his perspective is still more than likely not completely unsubstantiated. As such, rather than deeming the discussion pointless, we should be asking why he dislikes Waluigi.