Because starting from the 1980's corporate organisation was focused on managing resources, of which humans were a part that had to be dehumanized to fit with the rest of the theory. There was a brief phase where it was called HCM - human capital management, but that never caught on widely; so HRM it is with a focus on managing as opposed to organising and supporting. https://www.linkedin.com/pulse/evolution-hr-terminology-why-...

Human capital is even worse!