Well, he has a point. Lots of the lovely features of the Ozians are what Ken "Acolyte of Jabootu" Begg would call Informed Attributes: things we're told even though depicted events actually contradict them. For instance, in The Emerald City we're told that Oz is an egalitarian communist paradise where Ozma personally ensures that all goods are distributed fairly, and nobody wants more than he needs; but there's certainly no evidence of this from the distribution of goods we can see there.

In the first book, this is done intentionally; the Tin Woodman claims to be heartless though he obviously isn't, etc. But later on I suspect it was because Baum was making stuff up as he went along.