When players discuss grinding in MMOs, someone inevitably brings up this argument:
Guess what you do in every video game created? The same thing over and over and over and over etc.
FPSs? Shoot everyone who isn’t with you.
RPGs? Level up and kill big bad monster to get super duper helmet of the bear.
RTSs? Kill the enemy.
Platformer? Jump n' duck to the end.
Grinding is more than "doing the same thing over and over". If you continue the process of reducing games to basic physical actions then calling those actions "grinds", you should go down to the level of "computer games are just repeatedly pressing buttons and moving a mouse--they're not worth playing". By that same logic, communication is just moving your body in certain ways, so it's not worth doing.
The reason we play games isn't that the actions of doing so are inherently "special" in some way--we play games because they organize those normal actions into something more, something that has meaning to us. By removing the meaning through reducing games to "grinding keypresses", you completely miss the point of playing games.
The substantial error in logic made in this reduction-based argument that suggests “grinding” is indistinct from playing a game: it claims that if A’s parts are the same as some of B’s parts, those two things are the same. In truth, If you can reduce two things in a certain way so that one thing’s elements are a subset of the other’s, you do not establish a relationship of equivalence. A chair isn’t a wooden leg. A table isn’t a wooden surface. Further, tables and chairs are different, though they both have legs. Desks and floors are different, but they both have a horizontal surface. Two objects or concepts cannot be treated as equivalent if there is relevant difference between them; there’s clearly a relevant difference between playing a game normally and grinding, though grinding can occur while playing a game.
Games are more than pressing buttons on a computer and pleasant lights and sounds emerging from the machine in response. Games are defined by the mental process of play, which leads to physical interactions with the environment. Without play, we cannot differentiate games from other arbitrary sets of rules and goals. Trying to break down games into a series of physical events misses what actually makes a game what it is: the fact that people are playing it, and that the game has meaning to them through their play.
So grinding is not simply pressing buttons repeatedly—we can break down any computer game into pressing buttons repeatedly. Grinding is when the mental process of play breaks down because it became separated from the game’s meaning. It’s similar to when a word sounds wrong and seems to lose its meaning after you say it a hundred times in a row. Grinds separate the meaning from the gameplay by the sheer force of repetition. Since game design is focused on cultivating meaning, game designers should wish to prevent game systems from devolving into grinds.