Many people here forget an important rule : When a new market comes (here : SteamOS), the more people comes, the more it grows.
If important games like Final Fantasy games come here, not only they will sell copies because they are first, but this plateform will grow faster from its very beginning. Other companies and customers will come next.
Remember IOS, Android... or even Playstation or Xbox !

(sry maybe my english is not perfect)