I think your experience is largely true for professional web developers, but with the advent of things like Node that brought JS into back-end land, there are a

I think your experience is largely true for professional web developers, but with the advent of things like Node that brought JS into back-end land, there are a lot of traditionally front-end people spilling over into back-end and "full stack" roles, which often do require some basic level of competence with complexity analysis. When you make the switch from writing code to support UI elements to writing code to handle data processing, for example, you're going a bit beyond the standard coding bootcamp's toolkit. I think this is the author's point, and why he recommends that bootcamp grads (who may end up in situations like these) take extra steps to be prepared for whatever curveballs come their way in their careers.