The solution for this is to publish textbooks on demand. I know professors who do this, and they get reasonable royalties and a book they're actually pleased with and can change from year to year at no additional cost to their students.
At least in mathematics (excluding the cash cow known as calculus), professors really do care that their students don't have to pay ridiculous costs for texts.
"professors really do care that their students don't have to pay ridiculous costs for texts."
Sure a lot do, like the professor in the article, but that doesn't mean they all do. There are some that don't care and I'm sure others who haven't thought about it or rationalize the situation because it benefits them immensely.
That is to say making generalizations like that boils down the issue to "Professors care" vs "Professors take advantage of students" neither is absolutely true for the system as a whole.
But perhaps the mathematicians are on the far end of the spectrum, since their ideal work environment requires nothing but a writing utensil and a writing surface.
At least in mathematics (excluding the cash cow known as calculus), professors really do care that their students don't have to pay ridiculous costs for texts.