ADS doesnt have to have anything to do with low TTK, though. BF3 on normal is also too arcade for my taste, hardcore is doable
That said, I don't want 1 shot kills or so to Planetside and not saying that, but having ironsights does not mean that the damage model has to be "realistic".
That said, I could never even imagine myself playing Quake, games that arcade hold no value to me. You can't really say either which game takes more skill or if low or high TTK takes more skill, they are pretty much different skill sets.