The voters certainly do sometimes reject the government. The best example was the 2011 election, when the outgoing government dropped from 40% of the votes to 17% of the votes. The voters made their feelings very clear on that occasion. Now it is true that, with coalition governments, sometimes a government might not be thrown out in its entirety. Sometimes one bit of the government changes and another party stays in government but with a new partner. So it's not quite as clear cut as in Canada or the United Kingdom, for example, that one party is in and the other party is out. However, in practice Irish government, Irish politics, has seen a degree of alternation because we have two large parties traditionally that have alternated in government. Certainly it's true that, with proportional representation, coalition government almost certainly is the norm, and that does make a big difference—maybe for better, or maybe for worse—but it does change the rules of the game.
On July 26th, 2016. See this statement in context.