Ah, I see. So to say "I'm not defending claim X" sounds more like "I disagree with X" than "I feel confused about X". I don't know how universal that is.

If you already think he believes something for a reason you believe is wrong, you're not putting much faith in his rationality.

Really? You seem to be radically overestimating human rationality in general. We all likely believe things for reasons that are too weak to justify our levels of belief, or believe things due to cultural upbringing and other reasons which have zero actual evidentiary weight. Part of the task of becoming more rational is identifying those issues and dealing with them, especially the higher priority things that impact a lot of other beliefs. Everyone here, including myself, likely believes things for bad reasons. In that context, discussing where beliefs come from seems natural.

I think that wedrifid is one of the more careful, rational and thought provoking people here. That doesn't mean that he's a perfect rationalist.