Inheritance indeed can be pinpointed as the one major problem in problematic OO code. A lot of the comments here talk about abuse and I think that hits it on th

Inheritance indeed can be pinpointed as the one major problem in problematic OO code. A lot of the comments here talk about abuse and I think that hits it on the head. It’s not really a matter of knowing when to use or not use inheritance, but rather that the developers that do use it end up using it everywhere and a bad pattern proliferates into even more problematic areas, such as using inheritance for mock objects in unit tests.