I'll agree that democracy by itself is not good enough. You need to follow a good moral code along with it. Does not have to be a religion per se, but at least a Bill of Rights type agreement.
democracy is the idea that getting a bunch of people to gather to vote on a question can be expected to lead to the correct answer. this is a logical fallacy. no decisions should be made on the basis of a logical fallacy, not moral ones, not amoral ones.
more importantly to you understand how the comic i posed describes the mistake that you are making in the text that i quoted?