It is a player-centric view. I am of the opinion that people who consider getting game rewards faster through paid items "pay to win" are jealous (I am guilty of such jealousy myself). I mean, so what if someone gets more merits than you?
The reason why I say the standard should be what the game design reflects is that in the end, whether any one player thinks something is reasonable or not, they have to face the truth that whatever the devs think will ultimately alter the game around them.
You can care whether other players earn more rewards than you or you can not care. But MMO devs care, and ours specifically cared, and those facts will ultimately cause your gameplay experience to change. If enough people quickQ, the average datamined runtime for Q would drop and its base merit value would drop. If the average leveling rate dramatically increased the devs would have adjusted the difficulty higher or the rewards lower - they did it twice before (in both cases *increasing* reward rates to improve leveling speed because it was lower than their target).
Pay to win doesn't just matter in terms of player psychology, although MMO devs are also often concerned about that. Its also because it can become the new norm, and that has a direct impact on *everyone's* game play.
For most MMOs, its also true that you can accuse players of being jealous, but if it makes them less likely to continue to subscribe and play the game it doesn't matter if that feeling is valid or not. MMOs are not about teaching gaming morality, they are about convincing people to spend their valuable time and money on them because their entertainment value is deemed worthy. Its a careful dynamic balance delivering that value in an MMO where everyone's needs are different but in subtle and not so subtle ways everyone will be comparing what they get against what they perceive as everyone else getting. And fairness, as abstract and ill-defined as it is, is critical to keeping players around. A perception of unfairness is one of the most destructive forces in any multiplayer environment.