I also use controller more and more these days, but I think more games are just designed with that in mind, the bigger titles all pretty much being ported from console now. Even Diablo probably makes sense. I played Warhammer:Inquisitor a year or two ago, which I enjoyed quite a bit and after switching to a controller for it, found that it worked much better with the skill rotation (but like it and DIablo and such games: Grim Dawn etc, I just don't play them that long anymore and just get bored with the mechanics).
The rare FPS I play is still KBM, only, but I've played Witcher 3 all the way through with both--KBM is fine and works perfectly well, but it's clearly designed around a controller, like any of those actiony adventure games.