As you may have noticed from the textbook examples above, many of the definitions of fallacies are similar. This has to do with the fact that fallacies have a long history of being built up as a theory, and that up until today, people believe them to be important, so they continue to teach and spread them. Each definition does have its own unique reasons for what makes a fallacy an "error" and how it causes an argument to be "bad"-- this is a result of the authors, and how they are inherently tied to the knowledge they disperse and create. What these authors have been taught about fallacies, the time period they were writing in, etc. all affect how someone defines a fallacy. Learn more about this in my research.