Please do not call voting based on NXT assets democracy. It is capitalism.
From http://en.wikipedia.org/wiki/Democracy:
Democracy is a form of government in which all eligible citizens participate equally—either directly or through elected representatives—in the proposal, development, and creation of laws. It encompasses social, economic and cultural conditions that enable the free and equal practice of political self-determination.
Regarding a better approach: I currently don't have one, but I'll think about it. I'm currently thinking "One man, one vote" (http://en.wikipedia.org/wiki/One_man,_one_vote), but I see the implemtation problems with this.
There are different types of democracy, what you quoted is just one of them, and not the best one. I briefly outlined above why it's not the best one. If you're interested to know more, you should google different types of democracy, start with Greeks.
"One man, one vote" is a populist kind of democracy with a short historic lifespan.
Capitalism has nothing to do with it. Yes, it's capitalism, why, what do you suggest? We build communism here? One big country tried and got burned, thanx but no thanx.