When I was a wee little child in the early 70s, every large organization in America had a department that dealt with employee records, details of hiring & firing, employment verification, complaints, etc. And that department was called "Personnel".
When I got my Ph.D. in 1996 and went out to get my first real job, every large organization still had such a department, but now every single one of them was called "Human Resources".
What drove the change?
I am aware that there were any number of widespread name changes in American society during this period. Many of them were driven by avoiding offense or becoming more inclusive. An obvious example is the change from "fireman" to "firefighter". But this does not explain "personnel" -> "HR". On the contrary, that change would seem to be a move in the more offensive direction (does anyone prefer being a "human resource" to being a "person"?).
Furthermore, the change would have required work. Even big corporations that had been around forever made the switch. Someone would have had to spearhead the movement to switch. People got new titles. Signage was remade. Brochures were reprinted. Org charts were revised. A lot of people apparently thought this change was worth the effort. Even organizations for whom the bottom line is everything thought that such changes were worth spending money on. What made them think that way?
The 80s saw a great change in the economic landscape, most visible in the thinking of figures like Reagan and Thatcher. Limiting government spending and encouraging private enterprise were the main goals of their economic policies. In practice, this usually meant cuts to social spending and lower corporate taxes. A lot of this change still has consequences today, both in the US and the UK.
This didn't come out of nowhere, and it had its basis in the work of economists like Friedman. This time saw the popularity of economic theories like trickle-down economics and a general trust in an unrestricted free market, as a reaction to a general distrust of welfare and socialism. This also led to a shift in the economic thoughts on the role of corporations. The paradigm shifted from a stake-holder oriented model, to one focused on shareholders.
Basically, this meant that corporations were always meant to act in the interest of those who had money invested in the company, instead of those who actually had a stake in the company's actions, namely anyone else that interacts with them. It seems like with this change in corporate culture, a change in jargon would only be appropriate. In a way, it is meant to be dehumanizing, because that way corporate decisions seem more rational.