Why should I trouble to point a finger at my sheep as they pass through a gate going one, two, three ... and end up at two hundred and seventy-nine? Because while a flock that size looks pretty much the same from week to week, counting 279 one week, 274 the next and 268 the week after tells me something's going on that requires my attention. The flock may look the same, but the counts 279 274 and 268 don't, their difference is immediately apparent.
Smart eh? Who thought that one up? Not Russell and Whitehead or Plato, or any of the other thinkers named in the article. But I'd be interested to read any of them who at least made a utility like that central to their discussion.