Does he use it elsewhere or anything like that?

I would call players who expend time in lieu of skill "grinders." "Farming," on the other hand, is often a late-game playstyle which gets the best results (farming for rares to fully equip a build).

I mean the necessity to do this can be seen as bad game design, and maybe the players are dummies for picking bad games (although the Diablo and Destiny series are pretty well received), but this sort of thing is required to play at the highest levels...