There are already loads of non owner beans ... and honestly, I don't think it should matter if people are non owners or not. If they try hard, and the judge thinks they're the best owner, they should get it. If not, they don't. It shouldn't matter how many they own. :L
Being an owner/non-owner doesn't affect your ability to care for a bean. It's hard enough to win one already, without restrictions on who can tryout. Not to mention there ARE plenty of beans like that.
But really, imagine the uproar if a bean was released only for *owners*? There'd be a riot of the non owners! I think there are plenty of advantages for non owners already and what really matters is how much you care for the bean.
But that's just me.
uwu;