Which of his books have you read? He's written around three dozen…
I don’t agree with the implied dual premises of your question—that any valid assessment of the man’s thought must come strictly through reading his books. And also, that quantity has anything to do with quality. And, I’m doubtful as a general rule that reading someone’s writing is a necessary or even the most important way to gauge the quality of their thinking.
I don’t present the following as anything definitive, but I think it accurately captures my overall impression and the impression of many others. It’s from an amazon review of Lost Cities of Ancient Lemuria and the Pacific:
“A truly, deeply stupid book. Written as part travelogue, part 'investigation' into apparent archaeological anomalies in the South Pacific, the book fails in both areas. Childress seems to have been exactly the sort of traveler who has given American tourists such a bad name: culturally insensitive and just plain dumb. His 'insights' into archaeology and culture are trite beyond description; he displays no critical skills when examining 'evidence' and displays a delight in sensation over facts. The usual suspects get interviewed; Rex Gilroy, the Antipodean version of von Daniken, for example. This book is definitely from the school of 'thinking' that finds ordinary archaeology- all that hard scientific stuff and all that annoying ivory tower university educated analysis- far too unsensational. [In fact, this is what Childress essentially said in an interview at the Chicago Reader.] So much more fun if space aliens had done everything for us, and archaeology is just a matter of ordinary blokes running around like Indiana Jones manques having adventures and finding lost temples and God knows what. Read at your peril.”
I’ve heard several hours of him speaking, which seemed quite enough to make a solid first impression. This was followed up by online research of various claims he’s made.
It’s not that I don’t think he can tell an interesting story. It’s not that he can’t add color, description, and novel information to his subjects of interest. He may or may not help keep open a sense of wider possibilities in the face of academic conservatism. He’s more traveled than most people and has had a wide variety of experiences.
But, in my view, if one is looking for rationally and empirically vetted claims that produce significant and valid new knowledge in his respective fields, he’s not someone I’d normally pay any attention to. I’ve seen way too many questionable or dubious DHC claims for comfort. It’s not hyperbole in the least to characterize his lack of reasoning as appalling.
I don’t think he’s deliberately careless. It’s just that he gives every appearance of never having learned critical thinking skills. He’s engaged in ‘pseudo-inquiry’, which “seeks to make a case for the truth of some proposition or propositions determined in advance.” (p. 189 in Manifesto of a Passionate Moderate, by Susan Haack).