Its a power-balance thing. Managers have more power vis-a-vis HR staff than line staff do, thus are more likely to be able to get away with persisting in things that HR staff doesn't like. So, more likely a source of HR staff "despair".
Employees -- unless backed by a manager -- are more likely to meekly acquiesce.
Germany certainly hasn't - when you win, you typically get your legal fees and damages (as in: what the court decided you _actually_ lost). So there isn't _that_ much of a liability - the main concern for companies is probably that they'll have to stop mistreating their other employees, too.
OTOH, there's a separate branch of jurisdiction especially for employment related issues which is generally employee friendly and for the employee a lawsuit is free and doesn't require legal representation on the lowest level.
My personal view from my interactions with HR (as a manager looking at redundancy, poor performance, sickness) is that they're best viewed as the Employment Law team.
Maybe it's just a European thing but I've seen more HR professionals despair at the actions of managers than staff. Yes, they may help him/her get rid of you but what they're really terrified of is his ill advised actions which open the company up to a massive liability.