Not disagreeing with the core assertion in this post because I think the author is correct that you can absolutely over-engineer things. But one thing I don't quite understand.

> Some controllers had to do some things a little differently.

....

> And young me? I just kept going. Adding the proverbial knobs and pulls to my abstract class

Aren't the ways in which the concrete implementations vary supposed to be in the subclasses? One of the points of the abstract base class is to encapsulate common behavior. For things that differ, those belong in the concrete implementations. So _one_ of the mistakes here was to try to write a god class that could anticipate all of the ways in which the subclasses differ and to encode those into the abstract class in order to leave the subclasses as simple as having to specify the entity type.

I guess that was the author's point ha?