In today's trend of transparency, this seems like a typical stubborn and rigid old-world attitude that many HR departments and top managements are guilty of globally. A large publicly listed company is statutorily required to disclose employees with remuneration above 2 lakhs per month, while the contracts with directors are required to be approved by the Ministry of Company Affairs and shareholders. When the top people have their compensation in the public domain, does it make sense to hide the compensation, especially by issuing a directive, of people down the hierarchy?
An organization where human resources are converted into human capital by right hiring, effective nurturing, identified training, and, lastly, performance-based compensation/rewards through continual appraisal and evaluation that leads to awareness for further enhancement of knowledge would usually like to showcase its right compensation for the right performer policy.
Dealing with humans, the HR of your organization should know that it is human nature to compete to be better than others. Professionally, this gets satiated mostly through higher compensation, perks, and designation than one's peers. Also, working together for 5-6 days a week for 8 hours leads to bonding and close friendship when personal issues are freely discussed. Add to this the ancient human interest in the grapevine. It should be clear by now, from the above, that attempting to regulate such matters itself is futile.