so many course books are "inaccurate, ignorant and so inappropriate"

The course book market for teaching English as a second/foreign language is dominated by publishers from the UK and USA:

English language teaching (ELT) publishing as we know it today has a long and lucrative history, dating, according to Rix (2008), from the Longman publication of Michael West's New Method Readers in 1926, to the present day, where annual turnover runs to around US$194 billion (Jordan & Gray, 2019). Some of the sector's best-sellers, such as Oxford University Press's Headway series (Soars & Soars), have sold over 70 million copies (Ożóg, 2018) with OUP's English File (Latham-Koenig, Oxenden, & Lambert) selling over a million copies in China alone. Generally speaking, it is taken for granted that commercial publications in the educational sector are based on sound, accepted pedagogical principles.

(PDF) The Global ELT coursebook: A case of Cinderella's slipper?

Looking at a very popular course book in British language schools, the Cutting Edge series from Longman looks pretty reliable:

New Cutting Edge: Pre-Intermediate

And by now there are plenty of versions to look at online:

(PDF) New Cutting Edge Pre-intermediate Students' Book.pdf ( PDFDrive ) | Hamilton Obando - Academia.edu

Plus lots of worksheets available:

ELT base - New Cutting Edge Pre-Intermediate students' book

To what extent, though, are such publications relevant to students beyond Western European teenagers? But more than that, can these course books be considered "inaccurate, ignorant and so inappropriate"?

To take an example from Cutting Edge Pre-Int module 5, looking at appearance. There are attempts to compare ideals of attractiveness across cultures - but today, some decade since it was printed, the pages so feel rather patronising, if not disrespectful towards how different people understand physical appearance. We have surely moved on from finding it rather funny that the Dinka people of Sudan consider 'fatness' as a positive attribute?

This is indeed one of the limitations of course books: we are given a starting point (text, sentences, audio) which is restrictive and prescriptive as much as it is descriptive:

Jay Doubleyou: why are most teaching materials boring?

So, why not actually start with the student?! They have so much to tell after all...

Finally, here's an alternative view:

Global textbooks (GTs) - full-featured English language teaching materials containing a range of workbooks, videos, CD-ROMs, and online materials - have become a major feature of Teaching English to Speakers of Other Languages (TESOL)pedagogy in the 21st century. However, they are much maligned by some scholars as tools of cultural imperialism that damage local cultures and contribute to the learners' failure to acquire proficiency in English as a Foreign Language. This chapter uncovers a number of the sociopolitical dynamics that give rise to GT opposition, and questions some of the more strident claims of anti-GT scholars.

(PDF) Global Textbooks in Local Contexts: An Empirical Investigation of Effectiveness

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