Not all terms for describing electoral systems originated in political science. Some were developed (or at least popularized) by professional reformers seeking to build popular movements because history had made legislative adoption too hard. One of those terms is “winner-take-all.” Here is what F.A. Hermens says about it in written comments at the 1985 World Congress of the International Political Science Association.
Professor Longley makes some very perceptive remarks about factors which affected the demand for electoral change and the people who shaped it […] After an interval the energetic Enid Lakeman took over and intensified the work [of Humphreys]. She presided over a significant terminological change: The P. R. Society became The Electoral Reform Society, and the cause of reform was identified with that of P. R. Similar terminological changes were stressed: Calling plurality voting the “first past the post” system became more widespread, as did “winner take all” for majority voting. Thus the notion was conveyed that the former was as simplistic as the children’s game and the latter a grab for all there was. It is sad as well as significant that this terminology became frequent in academic writings; even the cautionary quotation marks are now all but gone.
By “majority voting,” Hermens seems to mean the two-round systems that tended to predate PR adoption on the European continent. “Majority voting” was a lifelong theme in his work.
Current use of “winner take all” inverts what Hermens observed 39 years ago, if we focus on the importance he attached to majority allocation. It gets used to describe plurality allocation and the Alternative Vote. (Less frequently it’s used to describe the opposite of what Maloy  calls a “multi-mark ballot.”)
Early exchanges like the above are fascinating because they were taking place alongside formation of APSA’s organized sections. They were shaping the scientific discourse of the decades to come.
I am not saying that any of the terms above — winner-take-all, first-past-the-post, whatever — should be banned. I’ve used them and probably will continue to do so, depending on the audience! After all, the terms were invented for public-facing communication. With such terms, however, it is helpful to remember the words of the reformer Walter Millard (with respect to the “short” ballot in 1943):
It was a slogan or label more calculated to arrest attention than to be accurate. It may be held to be more salient than logical, but it may have been the better for this; a great deal of the thinking of a great many people is of that type. At any rate it “worked.”
That the terminological move began in Britain is not surprising. I have suggested elsewhere (p. 28, fn. 7) that non-list approximations of PR (like STV and cumulative voting) were all but fated to win the advocacy battle due to long-established traditions of party government in Anglo democracies. In short, reform in said democracies is prone to “rage against the machine.” That’s because incumbents didn’t — and maybe still don’t — need it to prevent coalition raids and/or shore up party discipline. On that, I recommend two papers. The first contains a short section on why early party government might close off what I call an insulating PR adoption. (These papers also cover the problem of coalition raids under Hermens’ preferred “majority system.”)
More on party government. It is not surprising that Hermens piggybacks on Longley. The latter was a scholar of comparative legislatures. (Hat tip to Dan Smith at Penn.) Legislatures generally work more smoothly when organized by parties.
As for Lakeman, it also is not surprising that she led the terminological revolution. Lakeman (1903-95) would have experienced the Liberals’ replacement by Labour as one of the United Kingdom’s two leading parties. Her Wikipedia entry notes lifelong commitment to the Liberal (later Liberal Democratic) Party. She might have been looking for a way to raid the majors’ coalitions — possibly on transfers under STV.
Here, it may be helpful to compare the most prominent U.S. minor parties (cf. Karol 2019, Devine and Kopko 2021), as well as the newer Forward movement. All of these need ‘PR’ to break up existing parties. That is the opposite of using ‘PR’ to insulate what already governs. I have suggested above that these divergent imperatives are due to different trajectories of political development across Western democracies.
Further reading: Malcolm Baalman on the origins of the term “first-past-the-post.”