Because people are stupid, the difference in intelligence between the stupidest and smartest people is increasing, and democracy puts the decision making process in the hands of the masses which are intrinsically stupid
It's a whole system designed for "intelligent" (read: manipulative, immoral, rich) people to take advantage of stupid people, and it works wonderfully in their favor.
And there's fuck all an average person can do about it besides attempt to deal with the stupid people and convince them to do more intelligent things.
I hate it here. I want to be surrounded by people capable of reason already...