i agree with the author. i argue a preference for loose coupling over centralized abstractions. sure it's pleasing to compress the code, but if the use cases actually are sufficiently divergent (as well as bugs and externally driven changes) ultimately it becomes brittle, littered with edge cases behind if fences and both challenging and daunting to change.

ideal case: support libraries and then very simple duplicated code that is easy to read and modify. critically the core control flow should remain duplicated, but simplified by the support libraries.