I don't think that inheritance is bad per se. AbstractWindowButtonManagerFactory type of inheritance is bad. I think the reason is that people are not just good

I don't think that inheritance is bad per se. AbstractWindowButtonManagerFactory type of inheritance is bad. I think the reason is that people are not just good at constructing hierarchical relationships between abstract concepts. And once you construct such an elaborate hierarchy, it becomes very hard to correct things after the fact. So you end up with a mess as people add more functionality on top of an already ill-conceived structure.