I could play devils advocate and say that it’s bad for poor students because if authors are not fairly compensated then these authors won’t write textbooks and if they don’t then future students won’t benefit from having the textbooks.
When my courses had profs who had written the book, they'd have the school book store print and bind them to booklets, and sell them for close enough to cost, and also put up a download link for the pdf
Few academic authors are in it for the money.