This article touches on a core problem for democracy. But add to this the fact that the corporate media and the corporate parties (Conservatives and Liberals in Canada) prey on this weakness of the populace in order to sway the people to vote against the people's own interests. This makes anything that improves the democratic process, like proportional representation (or even procedures that take baby steps toward P.R.), critical to helping make democracy work better for the people. Better education and less corporate control of the media are also critical for democracy to flourish.
Some may try to argue, as if this is a different factor, that there are many people who just don't care enough about politics. This is not a different factor, but a result of the success of the propaganda of the corporate media/parties. Those people not smart enough to understand the importance of politics are convinced by the propaganda of the corporate media/parties to not care about politics. They will vehemently deny that they have been influenced, but they have (if they hadn't been influenced, they would care). These people end up not voting, and convincing others to either not vote or to spoil their votes in one way or another. This totally plays into what the corporate parties want - less involvement in politics by the populace = the more they can control politics. Politics in a vibrant democracy, is controlled by the people. In a failing democracy, politics is controlled by a few in government or in political parties whose true agenda is mainly to hold onto power by reducing the input from and control by the people.