There are organizations where it takes the threat of quitting to get one's salary, job duties, etc. reassessed. There is a lot of poor implementations HR processes out there - and poor implementation by managers, rather than company policy, often underlies the situation.

Many managers no more want to have negotiations about pay and advancement, than many employees do - there are two sides to the coin, many employees prefer the excitement of an affair with another company than trying to work out the existing relationship. The new company expresses their love; the old ignores the employee.

In other words, the situation described is frequently a failure of communication between supervisors and managers and their employees.