Is that why it's closed? Or is it closed for the sake of maintaining sales profits and to avoid fracturing the distribution channel?
We've got too much fragmentation already, between PSN, XBL, Steam, Android Market, iOS/OSX App Store, Windows Marketplace, Ubuntu One, iTunes, Amazon, Desura, EA's custom store, Ubisoft's custom store, etc. Most of these services are entirely redundant. Originally they existed separately as they targeted different platforms, but with the multi-platform stores being common-ish now, most of the rest only exist solely because some asshat marketeer wants to have access to user information that the other stores don't share or to better "control" market prices and the like.
The end result for actual users is almost entirely negative. Users want one place to buy apps/games, preferably with a Steam-like "one purchase, all platforms" approach. Users want a single list of all their friends, achievements, high scores, saved game backups, avatar customizations, etc. Users want to have just one account to remember and log in to. Users want only one entity responsible for securing their payment details. The community aspects of a fragmented "market marketplace" are hurt heavily, and the usability aspects of that fragmentation just frustrate users.
Releasing the server as FOSS has a myriad of user-oriented benefits inline with the tenets of GNU Manifesto and the OSI Mission, naturally. Releasing it so that the Astronaut can make his own fucked up fork does nobody except the Astronaut any good at all.
So, you want only one service selling you games? Be prepared to pay at least 100 USD for any simple game, and 500 USD for an AAA-game then... :P
Seriously, competition between "game shops", "app shops", "music download shops", etc. is a Good Thing™. What we need though, is a way to prevent the "big players" in "virtual shop"-land from monopolizing the profitable content and killing off all the other shops (which is close to what is happening right now, unfortunately).
If you go to the supermarket behind the corner, you expect to be able to buy Coca Cola, and not find a sign "sorry, Coca Cola does not want to sell to us anymore because they signed an exclusivity contract with Wallmart, which now sells it at 5 USD / can".