Wrong. It is my business.
You may like to make it your business, but then you get that information on your own accord. It doesn't have to be publicly broadcast to everyone any more than all the other HR information held about a person on file.
Just like universities, our school (or rather school association) works on pay scales or rungs, with clear performance expectations for given levels. So no need to break heads over salary negotiations and no matter what you get paid, you are expected to do your job. Doesn't mean we don't think we should be paid more, although the management overall seems less hostile and/or ignorant compared to the counterexample here, and are actually quite supportive.
The measure of productivity is often linked to results, not hours. If you can get the job done in 20 hours rather than 35, all power to you; if you need 50 hours to do the same job, that's what you need to do. Either way you're paid to do that job or task, not to churn out hours. The negotiation then is to reconcile between the workload expected and "hours paid".
If grievances are not being taken into account by management, it may be time to move on. If management care enough to recognise you are a valuable asset to them, then they might readjust themselves to negotiate much more fairly with you. This happened to one of our cleaning staff. She was going to leave because she didn't feel her superiors were caring enough about her. When the bosses got wind of this intent, they took her out for lunch. End result she has more agreeable conditions, a raise, and more importantly some acknowledgment from management.
If management do nothing to stop you going, then you probably know then how much they valued your being there.
I don't know if management rewards us well for hard work, except verbally and helping us to put together our cases for level advance, but in our line of work we work hard not for higher pay but because failure to achieve what we need to makes our jobs inexplicably more difficult. No one needs their job to be more difficult than it already is, unless you take pleasure in sitting back and watching the whole world burn.