Sony has yet to respond in any official capacity (despite being asked by many journalists) how this is getting on the PS Store (along with the other Steam Greenlight quality trash that's been going up there lately).
To put this in perspective, there's a few games on the PS Store now that couldn't even get out of Greenlight on steam. That's how bad they were. Why they are in such a rush to become Valve-level shovelware distributors, who knows.
The Xbox Store still has the "Creators Club" which is basically like the XNA/Indie channel from the last generation, so if you want pure Steam-style trash, it's all there, but it's kept in it's own section and MS is not actively marketing the games there.