I hate textbook churn. Gotta sell a new and slightly different edition every year.
In my upper level courses, yeah, I can appreciate it: when I’m teaching brand new stuff and assigning papers from the scientific literature to keep students up to date, then it’s reasonable to update the text every year…or every few years. But I teach introductory courses in cell biology and genetics, and nothing changes at that level — I have textbooks from the mid-1990s that would be perfectly acceptable now for first and second year students.
My genetics text is very annoying that way. The first half of the semester is basic Mendelian transmission genetics, and in principle I could use texts from the 1960s (later when we get into the fancy stuff, I might need one from the 1990s), but no. The publisher changes the order of the problems at the end of each chapter every once in a while. Same problems. Just scrambled around so I have to look every year to find where they are, and if I want to allow students to use old editions, I have to give them a list of 11th edition problems, 10th edition, 9th edition…it’s a pointless pain in the ass.