From what I heard, it’s because Springer et al. hired editors in India to cut costs…

The last springer book I've had is so poorly written that there is absolutely no way it was proofread. It is not just one mistake here or there. It looks like a quick draft with incomplete sentences, repetitions all over. Looks like those "cheap" packt books.

Looks like someone sent "fundamentals_of_math-e4-v2-final-finalv3-final.docx" to the printer instead of "fundamentals_of_math-e4-v2-final-finalv3-final-final.docx"

I published a book with degruyter and there is no proofreading at all. No support to get e.g. the colours right for printing. They only give you some example books, a rough latex template and minor advice on content and audience. Once it is published they will ask you if you want to prepare a revised version. It was OK because e.g. my students get a free ebook version anyways via the university subscription and I guess it is ok for the rest to pay the overpriced but well printed book.

If your students get it for free why not make it open access on wikibooks or something like that? The only reason people in academia were publishing the books as books was for resume stuffing but that was a different domain.

Actually resume stuffing was the major reason (not to get a job but rather for positioning oneself). I wrote it in my free time actually (my income on the book is about a 10th of the time put into it). That it is free to the students is just a nice side effect. The target audience is decision makers in smaller companies. You do not reach them via wikibooks. I guess I would have never written it as open access, because in this case I would have left it to others.

I would like to see a peer review/editing community for wikibooks btw, that actually would lead to better quality of books. distill.pub eg IMHO is great.

I've authored book chapters with Springer. I've used their LaTeX class and produced some nice looking chapters (imho).

They get "typeset" by SPI in Chennai by a non maths speaker, non-native English speaker and come back with errors in both the equations and words and author queries like "equation missing but we follow tex".

One professional mathematican I know in a suitably obscure area of number theory has started her own journal to get around it all. I'm in both the physics and medicine camps and have to put up with this bullshit. It's awful.