Writing isn't only coming up with knew ideas. Thats a concept. The concept might not be completely original but the acutal writing is not bad.
I mean, look at Oblivion. I can't think of one but I'm sure theres other stories where demons or something come from another dimension and attack. Even TW2 ins't completely original....being framed for a murder....throw in a king as the victim and it gets more specific.
No doubt about, details often vary vastly, I admit that. But in the big picture, they are extremely similiar. Even Dragon Age: Origin is littered with cliched wrting, as is the overall scope of the plot; muster a great army to defeat a demonic dragon and it's army. Basically the same thing as, again, Oblivion.
Take that elf assassing fellow, a slick and scheming lad who's loyalty lies where the money is, or depending upon what choice you make in the game, that it turns out that at the bottom of his heart, there's true kindness and love. And what about shapeshifter, I don't remember her name, but she's all secretive and reclusive, distrusting many of those around her because of what she and how she fears she may be outed, all while holding onto big secrets.
It's cliched. We've read of these characters for several decades in literature, they've already captivated millions of readers' hearts. The reason it's hailed as good writing, is because this medium is young, it needs to establish itself, find its footing, saturate and grow... Then, when the time is right, something truly great will come. But not now.
I'm not saying it's horrible and dreadful writing, just that it's been done for a long time.