Perhaps you may know people who need that. That is neither what I have said nor what I need.
It's more that I feel that a setting book should present setting information rather than spending page count on explaining why the way people may have been using the setting before does not fit the views of the person hired to present a 5e version of the setting.
It is my view that, if the person writing the book feels the need to apologize for writing the book, then maybe they shouldn't write the book. By the same token, if the person is using page count to tell me what is badwrongfun but also simultaneously making money on selling me something that they feel I shouldn't be playing... I guess it kinda feels like buying drugs from a substance abuse counselor and then needing to have a meeting with them about it the next day