While talented Linux administrators exist, there simply isn’t an abundance of them. Linux certification ensures a level of competency, but the scarcity of Linux administrators means that they are harder to find and more costly to acquire than Windows administrators, which exceed 1.8 million certified professionals worldwide. This scarcity requires companies to either (a) pay more for system admins or (b) re-train existing staff. Either way, companies incur increased costs.
As a result of this scarcity and the cost of Linux administrators, companies are experiencing unanticipated difficulties in maintaining Linux workloads. For example, Sucos del Valle, a beverage manufacturer in Brazil, experienced difficulties maintaining the security of its corporate network with Linux so much so that it migrated from Linux to Windows. Sucos del Valle's IT Manager, Douglas José Januário came right out and said, "We were really concerned about the lack of specialized employees trained in Linux who would be able to maintain our previous \[Linux\] system. We didn’t feel secure because we’d been unable to find certified personnel."