Marginalism is a bitch, sometimes

Saw this on facebook:

You see this with teachers and nurses a lot too. A lot of people interpret this sort of thing as society not "properly valuing" these contributions. Since this is public employment, that might play some role. But when you look at things from a marginalist perspective, you quickly realize that if you think the problem is not nearly as easy as getting everyone to "properly value" public servants or any other class of worker.