Maybe limiting to Hero alone is enough, maybe you need 10, 100 or 1000. I would suspect that the majority of users are bots, alts or other accounts that would make a democratic process unfeasible
Until the new forum is done nothing this complex will be implemented anyway, so either its really simple or its not going to happen. IIRC theymos was also against anything that might result in the forum holding users funds.
The majority of the bots that post noticeable spam are brand new accounts. However, I've seen some bots become even Hero members before someone notices that they're copying content from somewhere.
Update: Yes, that has crossed my mind as well.
