Besides the fact that it isn't even a game, but rather just an interface, how many games have had open betas? The problem with open Betas is they often get negative reactions from those that don't understand the difference between a beta, alpha, and full release game, and are quick to bitch and moan about it on the Internet, thus leading to countless unsubstantiated rumors to the quality of that game.
Personally, I'm glad Sony is spending so much time developing Home, as it appears to be growing vastly in size and scope, and if they rushed it to market imagine how all the naysayers would react then, given the high probability there would be countless bugs and glitches and lacking critical features.
