[an-honest-moose]

That is an incredibly dismissive and reductive argument to make. "Feeling sad about your job" isn't limited to burnt out software engineers with a safety net. It can also apply to, for example, someone stuck in a shitty, low paying job with few, if any, prospects for better employment. The lack of a path to a decent future can, in itself, be incredibly demoralizing, even if your present circumstances might be decent. After all, what's the point in continuing if I can see that it's all downhill from here?

[astrange]

That isn't major depressive disorder either. Even if those people think their life sucks, they're capable of, say, getting out of bed every day and don't regularly attempt suicide.

Russian serfs might've revolted when they got the chance, but they were more or less psychologically normal until then. Their society adapts to not kill them all. (Or they all become alcoholics or something.)