Of course it works. It works when, probably, 85 to 90 percent of the workforce gets intimidated when management starts putting the screws to them. Most people find it easier to do whatever management directs them to.
Why?
My guess is most workers are just intimidated. Most probably know they have recourse through the grievance procedure, but don't have the stones to follow through with filing a grievance. From the people I've worked with, many don't follow the methods closely enough, and are worried filing will put a bullseye on their back, and shoddy methods equals an easy way to suspend them. Laziness. So, it's easier to yield to the harassment than to fight it.
Some people don't have any knowledge about the grievance procedure. Sad but true. I would venture to say that the vast majority of those people wouldn't file even if they knew how.
Fighting harassment isn't for the weak, that is for sure. You better follow the methods and do your job the way it is to be done. Shortcuts will always get you. You also better be able to tolerate the daily push from supervisors about performance and the ever changing ways they want things done. You better be able to control your temper and behave like an unemotional drone when called into the office. Their strategy is to make you mad. They want to be up in your head.
Bottom line: harassment works. It works because it depends on apathy and ignorance. And the hourly ranks farm those two things like Iowa farms corn.