When students graduate today, some of them graduate with no student debt, many of them graduate with significant amounts of student debt. Students have six months until they're expected to start repaying the amounts that they've taken out to go and study. In many cases students within those six months need to find something that will start to pay the bills. Those students often are somewhat restricted in their ability to search for employment or their ability to be picky and choosy maybe in specific fields that they wanted to study in. This, as you were mentioning, creates situations where those who are able to afford to work for free are able to take jobs, especially in specific industries or sectors of the economy where that's the expectation. Those who graduate and need to start earning an income might have to take jobs unrelated or they'd be considered underemployed at that point.
On March 27th, 2014. See this statement in context.