Most of these ideas are tradeoffs. If a particular tradeoff is the right thing to do 80% of the time, then it is clearly a good idea. But if you understand it as dogma, you'll do the wrong thing 20% of the time.
Take the pizza example. Which is better, linear code or small functions? It's a series of tradeoffs. Once you get above a screen of code, or 10 ifs, functions become hard to read. Once the same logic has been written 3x, abstracting it is usually a win. Even if it is small. And there is a fuzzy area where it isn't obvious which is better, and debating it is probably a loss over writing it and moving on. Doubly so if you're defaulting to the same kind of decisions every time and so the style is consistent.
In a world full of pragmatic tradeoffs, dogmatism is rarely the right choice. (Unless you haven't learned the tradeoffs.)
My pithy description of software development is "a series of decisions in pursuit of a goal".
dogma invites people to stop using their critical thinking skills.
One of my favorite examples of this:
Everyone would agree that having a newborn in a car means safety is paramount. Everyone also agrees that left turns are less safe than right turns. No one would agree that this implies you should never make left turns in a vehicle with a newborn.
^But the above is how both security people and TDD proponents tend to act, as if there can be no risk assessment and critical thinking involved. We've all made right hand turns when we really wanted to go left because there was just too much traffic, even without a newborn in the vehicle.
Take the pizza example. Which is better, linear code or small functions? It's a series of tradeoffs. Once you get above a screen of code, or 10 ifs, functions become hard to read. Once the same logic has been written 3x, abstracting it is usually a win. Even if it is small. And there is a fuzzy area where it isn't obvious which is better, and debating it is probably a loss over writing it and moving on. Doubly so if you're defaulting to the same kind of decisions every time and so the style is consistent.
In a world full of pragmatic tradeoffs, dogmatism is rarely the right choice. (Unless you haven't learned the tradeoffs.)