I think you're missing part of the author's point. In the bash script, each command and flag being used does something and what they do is not obvious to anyone

I think you're missing part of the author's point. In the bash script, each command and flag being used does something and what they do is not obvious to anyone who is not well-versed in those commands and flags. The JS example is closer to english or pseudo-code, which makes it inherently more readable. It is not as terse, but it is also not esoteric like the bash script. Someone who doesn't know bash or JS will probably be able to understand the JS version more quickly.