I read the Gaiman quote as referring to "fool" in the sense of court jester, which seems to have more to do with status than intelligence although there are implications of both. Looked at that way, Psy-Kosh's objection doesn't seem to apply; it might indicate something wrong with our status criteria, but of course we already knew that.

The psalm, on the other hand, probably is talking mainly about intelligence. But the ambiguity still makes for a nice contrast.