Being compatible doesn't mean that compatibility is the path of least friction, especially when it clashes with good design. A good example of that tension is

Being compatible doesn't mean that compatibility is the path of least friction, especially when it clashes with good design. A good example of that tension is the final/open thing: Wonky frameworks abuse inheritance and force you to use open all over the place, but Effective Java suggests you should make every class/method final unless you specifically design it to be extended.