K/D or K/D/A fixation isn't just restricted to LoL or MOBAs in general. I remember how people in Halo: Reach and Hawken for example obsessed over their K/D ratio, to the point of losing more often than winning (especially in objective-based game modes) even though people always assumed high K/Ds meant guaranteed wins. I'll admit I don't have a lot of ethos on the subject because I'm still inexperienced with the game and learning about how to play better, but I remember a time I was on top of the leaderboard with deaths as Sion of all chars (still got a few good kills in though), but the other team I was dealing with was so distracted with my antics, that they let their guard down and ended up losing their Nexus. Moral of the story: K/D/A/ may help give an idea of how someone's doing, but in the end win/loss is more important.