>Are they light pattern people getting exploited? Why won't society raise their salaries, so more people will work as nurses or at least not resign
I would guess that most nurses get into the job because they want to help people, that seems like a really light pattern trait.
Society only very indirectly decides their salaries. At least in most countries right now it's a market mechanism that is ruthless. Of course there are other humans that may or may not have moral qualms. But as long as some people are ready to exploit others they have a pretty clear financial competitive edge (all else being equal).
If nurse salaries are low the economic answer is simple, it's because there are enough (or too many) nurses willing to take this job at that pay level.
The societal answer is not that simple. We actually want more nurses, because they are needed. We also don't want to pay more for healthcare, maybe we can't, America seems to be at the limit here, Western Europe is already close. So if you want more and better paid nurses without paying more, that only leaves shifting money from insurances, hospitals and pharmaceutical/medical equipment companies to nurses.
And to get to do that there has to be some market pressure or regulation.