It is neither predatory nor gouging, with TFA serving as perfect evidence. No one is compelled to agree to these terms.
Larger authors are not compelled to agree to these terms sure, but if you’re a smaller publisher or author trying to get your work out there and noticed, it can be hard to gain ground without selling via Amazon.
OTOH, I published this book after about 7 years of weekly blogging, mostly about Emacs, so I think that everyone who might be interested in my book could easily know about it. And an intermediate Elisp textbook is rather a niche thing.
It's not as if Amazon is unaware, they'll fix their pricing system if enough people reject it.