The reason: the meaning of the word is frustratingly difficult to pin down.
Churchill supposedly said something to the effect that "democracy is the worst form of government around, except for all the others." And yet, he was the prime minister of a country, the political ideology of which places, in theory, sovereignty in one person. More to the point, he was part of a political system that elected representatives to a parliament and that in turn elected a leader to run the government. To my ears, that sounds like a republic. In other words, laws would be passed every year on which most of those affected by such laws would not have had a chance to vote.
It gets even weirder: sometimes people who cry "democracy" mean majority rule, sometimes they mean minority right. Sometimes they mean both, on the argument that on most matters, the fairest overall outcome is usually the outcome favored by the majority but that on issues concerning basic rights of an individual, the minority should have certain guarantees. Maybe that statement of the matter is about as commonplace a notion of what "democracy" is as any other, and is probably the most serviceable.
Still, we have the spectacle of people stressing, with very little consistency, the minority right versus the majoritarian arguments. I cannot number how many Democrats I heard in 2000 claim that Mr. Gore should have won because he got the most votes. Of course, there were very real issues about the actual tally of votes in the state and about alleged disfranchisement of large numbers of blacks. But the argument I heard, probably most often, was that Mr. Gore got the most votes. Meanwhile, Republicans pointed quite accurately to the rules of the Electoral College, which allow for such an outcome.
In 2004, the situation was potentially the reverse. If Mr. Kerry had won Ohio, he would have (if my math is correct) won the presidency but probably would not have garnered the majority of the popular vote. Now the cry by one Democratic cheerleader I know is that Mr. Bush's administration stole the election and rigged the voting machines in Ohio. (His blog is here, although you'll have to hunt in his archives to find the discussion of the Republicans' supposed machinations.) I don't claim that my friend speaks for most Democrats (he doesn't even speak to my memory of how most Democrats reacted Mr. Bush's reelection), but the crux of the argument is that "democracy" was sinned against because the rules weren't followed. Maybe they weren't followed, but Mr. Bush got the majority of votes.
Maybe "democracy," at least as people tend use the word, is just a synonym for "mobocracy" after all.