I think that's reflective of how experience levels change your perspective on how to approach a problem.

Someone with command line experience that is mostly a user of system utilities would think passing the output of ls through a filter is the way to go whereas someone with C experience that already has insight in how Unix is architected would do something more along the lines of what the author is doing. That's pretty much how unix got built to begin with, and probably both parties would qualify their solution as a 'hack'.

It's all perspective.