Here is an argument I'd like to see in the next introduction to logic text I come across:
Someone's putting out a second edition of a book ought to be an embarrassing thing. After a second's worth of thought they emerge as admissions of having initially released a flawed book. 9th editions ought to be really embarrassing.
In the sciences it is understandable. New research demands updates, and new paradigms and equipment mandate new methods. This whole thing is actually not applicable to cases where real new events and findings mandate new editions of old books which are otherwise well made. But there is little excuse in the humanities, especially in something like an introductory philosophy, logic, statistics, history or classic text. There is a really big problem in all those ethics textbooks that get reissued. An ethics text from 20 years ago is probably just as good as one written today. The problem is that in itself it is immoral.
Generally a second edition says 1) my first job is good and this second one is inferior, or 2) This is just a re-wording of the first edition, or 3) This edition is better than the last one. If this new edition is inferior, then of course I do not want it. I also have no interest if I am just looking at a re-worded version of the first. What is the point of that? If the newer edition is better then it says that either the author was originally sloppy, or it says that the author was deliberately worse in his first endeavor in order to improve it later. If the author was sloppy the first time, I am not that likely to assume that the second try, even after she has heard all the criticism is much better. That is what the writing stage is for. If the author was deliberately inferior the first time around then the author is evil. The reason the author is evil is that there is an assumption that a person does their best job the first time around when writing a text book. Generally this is stated in the introduction or on the back cover by someone who hails the book as a pedagogical revolution in the field of introductory texts. So the evil comes because there are millions of books out there and to get me to read one of them, I must be convinced that the author worked hard making the experience worthy. Moreover, students rely on these texts for their futures.
If there are mistakes in books, sufficient that it warrants a new edition, the author and publisher should recall the original text and offer to exchange it for the new one with no charge and point out the changes, so one need not waste their time looking for what poor information they were given the first time. But since they don't do what they ought to do, I do not trust them. And I refuse to buy the book of one I do not trust.
Now, I am not so naive as to not know the real reason for the constant re-issuing of new textbooks. These are generally demands by the publisher. The publisher says that if the author/editor does not release a new edition, then they will not keep the book in print. The author wants the book in print, so they play along. The publisher wants the new editions because students tend to sell their texts back at the end of the semester to get some cash and to promote recycling. The books then get resold the next semester to the next batch of students who pay a lower price, but with the publisher getting nothing.
Perhaps a solution might be to have the publisher "rent" books for the semester.