Most of the HR people do not first think about the long term company plans when selecting candidates, legal stuff or anything else when it comes to hiring. Most of these problems are related to breaking the necessity for formal education, thus making this position open to kakistocracy and hurting the company in the long turn.

TLDR; The decision of managers in general to have HR from all forms of education, except from legal, has been the main reason for HR ineffectiveness, bias, discrimination and other problem among them prejudice that HR is on the side of the company. When you don't have knowledge, and you work in HR, you need to prove loyalty to the management and be executioner of a lot unpopular decisions, and obedient. They don't understand the legal background for a lot of stuff or managerial, especially when it comes to layoffs. So they only option is to either listen or get replace. And, this will stay the same, since any HR will not allow any HR candidate to get hired in the company that has more knowledge. Those that do not have the knowledge will fight tooth and nail to keep their job despite their lack of knowledge.