It's just reality that (most) companies with no transparent in their compensation, existing employees will be put on the salary bracket that will give the company the most leverage - either by being able to dangle a good counter offer (whenever the employee is about to transfer to a different company) or simply saving on salary expense.

Corporations will always mark an employee simply as an entry on their ledger. When the time comes to get new hires on similar work level, they know they need to up their game in terms of how much they can generously pay while still maintaining the bottom line of the organization.