Wisdom of the crowds

I was always skeptical of democracy (especially after following Indian politics). The best argument I have ever heard in favor of democracy is that the alternate models have greater risks involved. When I chanced upon this book “the wisdom of crowds” (http://en.wikipedia.org/wiki/The_Wisdom_of_Crowds), I was curious as to what the author had to say. The following four points are prerequisites for a crowd to produce the correct judgment.
1) Diversity of opinion: Each person should have private information even if it's just an eccentric interpretation of the known facts.
2) Independence: People's opinions aren't determined by the opinions of those around them.
3) Decentralization: People are able to specialize and draw on local knowledge.
4) Aggregation: Some mechanism exists for turning private judgments into a collective decision.
In the Indian context, I see “Diversity of opinion” as the biggest bottle neck. I am not sure if people have information at all (hopefully this will change after RTI is more popular). As an optimist I am hopeful things will change for good in future.