System hardening is a crucial practice for enhancing the security of a Linux operating system. When you harden an OS, you minimize its attack surface to make it more difficult for attackers to compromise your Linux system. You also decrease the likelihood of exploitation, malware injection, or unauthorized access. When the attack surface is smaller, the risk of security breaches diminishes significantly. Organizations handling sensitive data (such as Personally Identifiable Information or financial records) face significant fines for data breaches. Hardening helps meet compliance standards and avoids reputational damage caused by security incidents.

In summary, system hardening is essential for safeguarding your Linux OS, especially when dealing with sensitive data or critical infrastructure.