They're helpful of employees and managers only insofar as it helps the company. And even then, only insofar as the company values that help. I've never seen HR go to bat for an employee, against either a manager or against the company. The implication that they're not mall cops (but there to make sure workplace law is followed, i.e., they are cops of a sort) is actually quite apropos; they are there to protect the establishment and the status quo. They are not there to help you.