We are talking about different things. If you want to use inheritance inside your module, behind a reasonable API, in order to re-use common logic, I won’t bat

We are talking about different things. If you want to use inheritance inside your module, behind a reasonable API, in order to re-use common logic, I won’t bat an eye. I won’t know, I’m working with the public part of your module. If you structure your code so that people in my team can inherit from your base class (because you didn’t make an interface and left everything public), and later you change some of this common logic, then I will curse your name and the manner of your conception.