In this brief video, Matt Damon is quizzed by a reporter who claims that he's a good actor because he knows he'd be fired if he did a bad job, while teachers, with job security, have no such incentive. He persuasively lambastes the reporter, arguing that the reasons people do things — especially "shitty salary" jobs like teaching (but also arts careers, which have a very low chance of succeeding) — are much more nuanced than a mere job-security-incentive "MBA" model would suggest.
It's a very illuminating example of a clash of ideologies. Damon, after all, had no "rational" business becoming an actor, since he was almost entirely certain to fail. Now that he is a multi-millionaire, he has no "rational" reason to continue acting, because he's assured of financial security forever. Clearly, Damon is someone whose lifelong incentives are not about "job security." Rather, his motivations are vocational — he does this because it fulfills him.
And that's the case with most of the teachers I know. The important thing about a vocational model of incentives is that it can be undermined by the "rational" model preached by those who accuse teachers of sloth created by their "job security." That is, when you go around calling teachers featherbedding losers who only do the job because it's so cushy, you scare away all those people for whom the dignity of the vocation provides the low-cost workforce upon which the educational sector depends.