Exclusives aren't consumer-friendly but they shift boxes. Everyone knows if you want to play a Mario game you need a Nintendo.
The exclusives ship has sailed for the Xbox now so the best they can do is try to compete with the new Steam Machine with what will essentially be a PC and allow all storefronts.
It seems Valve has gone for an entry-level machine while Xbox is going for a premium one so it'll be interesting to see how it all pans out.
Entry-level gaming PC is still quite high up there on the performance scale compared to consoles. They haven't announced a price yet but it'll hopefully be similar to current consoles on the lower storage model. Anything higher will put it in range with existing prebuilt gaming PCs.
It will be interesting to see how the market will determine whether subjective “fun” is the same in an entry-level versus a premium experience. Short of some ego boosting element, the experience is likely the same.
The exclusives ship has sailed for the Xbox now so the best they can do is try to compete with the new Steam Machine with what will essentially be a PC and allow all storefronts.
It seems Valve has gone for an entry-level machine while Xbox is going for a premium one so it'll be interesting to see how it all pans out.