A couple factors are in play here:
First, the shortcomings of the book may not have been discerned. If only a small number of students get the simple potions wrong, then the published recipes for those books will be perceived as correct.
Take, on the other hand, a potion whose published recipe is incorrect. Some of the students, while thinking they are following the instructions, actually do something very slightly differently, and wind up succeeding. One of two things could happen here: Either the potion gains a reputation as being very difficult, or the community concludes that the recipe is incorrect. The former can easily become the prevailing opinion, even though it is quite wrong.
Then along comes Snape, who has such a gift for potions that his notes were sufficient to turn Harry from excellent to outstanding. He's finding all of these small places where the published recipe is just slightly off, and his corrections fix them.
Second, getting the establishment to change its mind is a process that is as much political as it is factual. Real-life history has more than a few examples of people who come up with an innovation that is rejected because it does not jibe with conventional wisdom, and only much later is it finally admitted that this "maverick" was right all along.
If as Potions Master he had found a way to stop unloading his issues onto his students, he could very well have become Hogwart's most popular teacher, and he would have been in a very good position to challenge the orthodoxy and get the books corrected.
Unfortunately, he was a bullying piece of work.