Compare it to the term 'tackler' then. Who are the tacklers in our side? The technical answer is all of them, though obviously some players are better tacklers than others, which is a statement about capability. Then there is also the question of roles - a winger or fullback who would be lucky to attempt half a dozen tackles in a match is obviously not in the team for his tackling. However a middle forward who goes two or three sets of six without a single carry (but makes 0.5 or even 0.6 tackles per minute) is clearly being used as a 'tackler'.
It's the same for playmakers. Every player has some playmaking ability (they can all draw and pass) but the difference between two given players could be vast. The best playmakers are used at first and second receiver, meaning they wear jerseys 6 and 7 (and sometimes jersey 1 - i.e. Coote and Moylan). Some other players have some decent playmaking ability but they are needed more for their running (e.g. Ma'u, Edwards, Takairangi), so they play wider. They are therefore not in a playmaking role, and any playmaking they happen to do is incidental, contingent on opportunity.
I understand you know all this and are just pissing about terminology. You need to accept the game has changed, and talking about playmakers and primary kickers and so on is more useful these days than old fashioned terms like 'five-eight(h)', that straitjacket one's thinking about the game. It's the same when talking about 'props' and 'locks' - it leads to the expectation that there must be two of one and one of the other on the field at all times, and it doesn't reflect the way the game is any more. It was the same again with Glenn Stewart being heralded as a 'ball-playing lock' (because he wore jersey 13 and had obvious playmaking ability and remit) even though Stewart was playing the same position (right edge forward) as a bunch of merkins wearing jersey 11 or 12.