A good, easy to understand codebase is one that has a minimal number of components that interact with each other in a well-organized and easty-to-understand manner. Those components, in turn, should each be made of a minimal number of sub-components that interact with each other in a clear, well-organized manner. And on down until you hit bedrock. Doing this is essential because it sets up boundaries that limit the amount of code and interactions that you need to juggle in your head at any one moment.
A programmer who doesn't understand this will produce horrible, tangled, tightly-coupled code regardless of whether they're doing it with a boiling soup of global variables or a boiling soup composed together from tiny "well-factored" classes that all implement interfaces containing only a single CQRS-compliant method.
I'd submit that there's another level of programmer, let's call it the SubGenius programmer (because the term tickles me) who thinks that levels 1, 2 and 3 programmers all share a sloppy work ethos and need to spend more time stepping back to keep an eye on how the forest looks instead of obsessing about trees all the time.
