Well in fact I've tended more and more to this bare kind of coding as I've aged (and hopefully gained experience). Many of the seatbelts (like assertions) I've actually hit at some point or another (so they turned out to be useful in these situations), but on the other hand they allowed me to be more sloppy in my thinking, writing more complicated code, which I feel could be a net loss in productivity.

Then again this is just some example code on a website, so it's natural that it has to be done a little more straightforwardly than you would write it in actual practice.