Some people are incapable of understanding context and trade-offs. Every rule must be either “always” or “never”. Always use inheritance! Oh, it caused fragil

Some people are incapable of understanding context and trade-offs. Every rule must be either “always” or “never”. Always use inheritance! Oh, it caused fragile code in this instance. Lesson learned - never ever use inhertance! And so forth. In this case, the author is confusing de-duplication with creating a particular abstraction, and when the abstraction turns out to be a bad fit for the problem, they decide code duplication is actually fine. This is the wrong lesson.