I don't think it's esoteric, I just don't think it's used much in real-life, day-to-day software engineering as practiced by most professionals. I didn't mean to imply it's a high hurdle, just that IMO a minority of actual SWE's are going to bust out the proverbial slide rule, and anecdotally it seems like they have a lot of options.

That it's a year-2 undergraduate course for some people argues more for forgetting than remembering it, if you're not using it regularly.