Buried in the "2.11 Frequent rewrites" section, but a great hack for "productivity via a sense of ownership": "In addition, rewriting code is a way of transferring knowledge and a sense of ownership to newer team members. This sense of ownership is crucial for productivity: engineers naturally put more effort into developing features and fixing problems in code that they feel is “theirs”."
If you have engineers with physiological problem of “not invented here”, you have a very serious issue. I am currently seeing this in real time in one of the projects and I was told almost exact same words as “reason” to recreate what we already have and working beautifully. It was clear to me that some developers are just too lazy to dive in to complex system. They get ticked off by one imperfection here and other over there and immediately run for exit shouting “I could do so much better”. Instead of understanding why things are the way it is, they fantasize about how they can one up original authors and claim their own hero title. They go on to throughly underestimate the time to recreate what has taken years of learning. So they spend next many months sweating out, copy as much code from “old” stuff as they can, dropping important feature here and there, adding new and old bugs - very often arriving at more or less same place they started off. Meanwhile competition has moved on to V2 laughing their way to the bank and customers scratch their heads why you are still stuck in same place for so long. Then our new “owners” gets their promos after massive marketing of how much better everything is now. But to everyone’s surprise they soon leave the project because working on bugs and incremental features has became boring and BTW, the new stuff is just as complex as old stuff. New devs roll in and we start the whole cycle again.