Every MMORPG game turns into some form of grind in endgame until the new content comes out. I'll be playing this game until I clear all the maps, which I haven't yet. I'm really good at economics in a game. I'm good at making money, trading, and making profit. I suck at actually playing. AFK shops here are extremely easy to make profit from. I started coming here onto the forums and the economy on forums is crazy inflated, but I'm trying to earn the mana to convert into MK2s to convert into Cubes so I can get some better gear to do harder maps. I'd grind my own gear if I wanted, but I make better profit selling what I find then finding something else from someone else.
Anyway, that was a rant. My point is, if it isn't a game with an ending, a grind always begins to happen where you just wait for the next piece of content or until you just start pushing the limits of a game.