Many managers do not like employees to talk about pay, unless they are the ones starting the conversation.
Salaries can be a sensitive topic in the workplace, and a lot of the time, that is because companies prefer it when employees do not know what everyone else is paid. Even the employers who do claim to value pay transparency can end up being weird about it, although it is often enlightening to understand who gets what kind of money.
We all know that most people are just doing their jobs for the paycheck, so perhaps that is part of the reason that management is sometimes cagey about what everybody gets paid. They do not want to have any conversations about raises getting out of control.
However, if, for whatever reason, they think that somebody is being paid too much, they are usually more than happy to make it known. Pay cuts are one of the main reasons that employees may choose to leave a job, but many bosses are willing to take the risk anyway. Ultimately, there is almost always somebody who is willing to do the work for cheaper if you leave. Knowing your worth is important, and sometimes it means taking business elsewhere.