Adam, the length is no problem at all!
Like I said in my response to Linda, I think there are two different definitions of “passive income” at play here. One definition, which is the one you and Linda and the textbooks are using, is “income that is not generated on a per-hour basis.” That kind of income quite obviously exists.
However, there are gurus and hucksters out there selling a different definition of passive income that looks a little more like “income that you only have to do an hour or two of work for and keep earning forever!!!” My intent with this article was to explain that no, every business requires work of some sort or another on a regular basis, regardless of if it’s a per-product or a per-work-hour basis.
P.S. Writing on a beach for Medium would be passive income, because I’m not paid on a per-article (per-work-unit) basis, but most freelance writing isn’t passive, so I take your point (: