People that think this is a sound business decision on both ends are only fooling themselves. The developers included. This is not something that promotes a prosumer attitude for having healthy competition.
How epic can stregthen their store is to do it the way valve started out which is have games from your own publishing that you own on your storefront. They don't own anything they just are making a storefront exclusive deal.
Valve started out with Half-life, Halflife multiuplayer that they then expanded when they got counter strike on there. Then had the orange box with team fortress 2 which blew up, followed by left for dead 1 and 2, portal 2, dota.
That's what they need to do, locking games for 1 year exclusivity is a shitty thing even if developers are getting good deal, it's not a long terms good idea to force people to come to your store because you locked a game that originally was going to be on multiple storefronts, or at least sold key wise on different sites.
All this does is show they are trying to force you not compel you to buy games on their store. They should have just concentrated on making a bunch of really big interesting games on their store specifically MP games.
Hope steam soon responds with better deals, or unionization for studios happens where they can make their own terms of distribution.