When reading this I was thinking that this distinction sounds more like what I know as profit center/cost center. I was glad to see a sidebar mentioning that he thinks its related. Maybe its more common to use that terminology in finance, which is really the only industry i've worked in. I've not heard line/staff used in this way but profit center/cost center is well known.

I will say that I don't really agree that profit center/cost center is less clear terminolgy or doesnt have the right boundries. I'd argue the opposite. It's a pretty direct description of why any distinction exists at all. It's also pretty inuitive that its preferable to be in a role tied to how the company generates money. Line/Staff terminology requires nice blog posts to explain what those things are. Maybe in a military context it makes sense because there is no profit center per se, but for industry, using line/profit terminology is just a whitewash of profit center/cost center, which is imo the real distinction.

Of course the classification of profit/cost is not perfect as there are jobs kind of in the the middle, like say if you are an internal recruiter (you recruit profit center people too so...) but I don't think those roles are easier to classify as line/staff either.