There is one single thing that the structure and choice of commands in code cannot communicate: intent. For most parts of the program this doesn't matter much,

There is one single thing that the structure and choice of commands in code cannot communicate: intent. For most parts of the program this doesn't matter much, because many programs are conventional and do pretty much the same things; so the programmer can reasonably guess why the code is doing what it does if you have already seen similar programs. But if your name and variables don't explicitly explain what each code section tries to achieve, there's no way to figure it out what it's supposed to do and why it's coded the way it is, if you don't already know that. From the code itself you can only learn what the code does, not what the developer intended to achieve; if you don't know the latest, there's no way to tell if there's a bug in it and it's working in a wrong way. This is specially important for the parts of the program you don't understand, which are the ones where you would benefit the most from proper comments/explanations, i.e. literature.