The first definition is the inherently negative common usage when applied to person-to-person or entity-to-person relationships.
Applying the second definition to the labor market would mean every worker is being exploited, because no profit-seeking corporation (or resource efficient government program) would keep a workforce that is a net loss to the organization.
> Applying the second definition to the labor market would mean every worker is being exploited
No, it means the labor side of the labor market is being exploited by capital. It means the capital side of the labor market is being exploited by labor. And yeah, that’s an accurate and correct use of “exploit.”
Are you sure this labor pool isn’t being exploited?