Most people in Western liberal societies think that democracy is a good thing, especially when compared to the alternatives. People generally like to be self-determining, and democracy seems to be the governmental structure that is most conducive to these aims, as opposed to various forms of totalitarianism.
This is all well and good. I'm a fan of democracy myself. However, there seems to be a sense in which people take democracy for granted. They just assume that it's a form of government that will run by itself and steer us toward the most optimal state of affairs. It's similar to a laissez-faire perspective on the free market.
This attitude is mistaken. Democracy is designed to execute the will of the people. How well it achieves the best ends for society will depend on the moral and intellectual quality of the citizens participating in the system.
This is the part that many people take for granted. They, either explicitly or implicitly, shirk their responsibilities as citizens. Such responsibilities include more than just going out to vote and paying your taxes. The responsibility of a good citizen also includes being the type of individual that is capable of making well informed and well reasoned judgments, and thus also includes the responsibility of training to become that type of individual.
Without this ability to think independently and to participate in rational discourse, democracy fails and becomes a more subtle form of totalitarianism.
In totalitarian forms of government, either one or a some group of individuals coerce the citizens to behave in some way. Usually the level of coercion, and the extent of activities to which it is applied, is seen as way beyond acceptable. People like to think that they have control over their own lives, and not being explicitly coerced into behaving a certain seems sufficient for having that control.
However, there are at least two ways for someone to not be in control of their lives. There's the explicit, gun to your head type of coercion. However, there is a sneakier to get someone to do what you want, and that's through various forms of psychological manipulation.
Someone who shirks their responsibility as a citizen and fails to think critically about political issues becomes more susceptible to various forms of psychological manipulation. In being psychologically manipulated, they lose control over their lives and are no longer expressing their own will, but rather expressing the will of those doing the manipulating.
The sad thing is that those who being manipulated don't know that they are being manipulated. They still believe that they are in complete control over their lives. There's a term for this kind of phenomena from Jean Paul Sartre called "bad faith" (also translated as self deception). Bad faith occurs when individuals fail to see what is actually true about themselves and instead act on false beliefs about themselves.
Members of democratic societies who fail to participate in rational discourse or deliberation act in bad faith. The believe themselves to be free citizens, when they are likely to be subject to manipulation. In a significant sense, they are no longer really free.