A good chunk of great advice is obvious things that people still fail to do.

That's why a collection of "obvious" things formulated in a convincing way by a person with big street cred is still useful and worth elevating.

Also, "why these 5 in particular" is definitely not obvious -- there are a great many possible "obvious in some sense but also true in an important way" epigrams to choose from (the Perlis link from another comment has over a hundred). That Pike picked these 5 to emphasise tells you something about his view of programming, and doubly so given that they are rather overlapping in what they're talking about.