Even in Kyoto

Citation expectations absolutely differ between (and within) academia, journalism, popular publishing, and the law--I agree and do not roll my eyes.

The American legal system is set up to expose truth through the adversarial process; no one would ever dream of trusting the citations in one side's brief to tell the entire, nuanced story or legal argument. Whether it is a useful form of truth discernment or not is beyond the scope of my comment.

But what kind of truth are you expecting from a book exploring a potentially elucidating but nonetheless simplistic dichotomy such as introversion/extroversion? The book is at least partly a cultural narrative, so far as I've gathered, so different citation formats may actually be appropriate in different excerpts. I expect the endnote style may be a compromise between the vastly differnt approaches employed throughout. I have less sympathy for not showing your brackets and ellipses, however. That's just expecting your reader to be lazy.