It's all economics
Read [link|http://economics.about.com/cs/macroeconomics/a/logic_of_action.htm|The Logic of Collective Action]. Groups find it difficult to organize for their collective good, even if they all know what it is, because it is in each person's interest to punt and leave it to everyone else.
This isn't about people being good or bad. It is about basic laziness and self-interest.
The only solution which has been demonstrated to work for this is to create individual incentives to put out effort for things that we all find worthwhile. However there is an inherent tension in making sure that it is not overly worthwhile to put out effort for things that most of us would rather not see. Like theft, political manipulation, etc.
I say overly worthwhile because there is a certain background amount that most of us just accept. But we all have our limits, and our limits are routinely exceeded until we (hopefully) find it worthwhile to pushback.
Cheers,
BEn
