I think the flipside of this is people liking to belong to groups. Most of the time belonging to any group with a properties that are essentially homogenous across the members involves some suspension of disbelief. Once people have made that leap and accepted whatever core values those are, they in turn define themselves in those terms, ignoring the fact that they weren't rationally vetted or arrived at through independent thought on the way in. Then if you've got some logisticians among the group, they'll go to great lengths to systematically rationalize the things that they mostly accepted because they're a part of that group. (I certainly do.) This goes from anything from political activism to religion to free software.

This of course isn't necessarily bad or wrong -- in fact I think society would scarcely function were for it not for a modicum of such behavior -- but it does mean that people aren't having these debates in the way that they would another debate -- because they've already know the answer, they're just trying to convince others that their opinion isn't stupid and wrong.