The issue isn't the interfaces; it's that there is only one implementation (the base classes) per interface—so why even bother having an interface? Otherwise, I agree with you to a degree.
The main issue with the codebase is that if you want to, say, change the behavior of a Book, you have to go change the behavior of some base class (after working out which one is actually being called). This base class might be used in a Clock, Field, or Filesystem as well—something so conceivably far away that their similar behavior is a coincidence and not really related at all. Then you get to argue with the architect about whether "reading a book" is different than "reading a clock."
The main issue with the codebase is that if you want to, say, change the behavior of a Book, you have to go change the behavior of some base class (after working out which one is actually being called). This base class might be used in a Clock, Field, or Filesystem as well—something so conceivably far away that their similar behavior is a coincidence and not really related at all. Then you get to argue with the architect about whether "reading a book" is different than "reading a clock."