Security Versus Convenience
While the sysadmin is responsible for the security of the computing systems, it is important to remember that the systems exist to further the goals of the organization and, in most cases, it is the users who are contributing directly to those goals. In a real estate agency, for instance, the user group will include the real estate agents who are actually selling property. The sysadmin is essentially paid out of their success.
In any environment, security costs. The cost may be measured in dollars, in effort, or in some other quantity. If the cost of security interferes too much with the user's efforts to achieve the organization's goals, then the security is self-defeating. Worse, the more your security measures interfere with the users' work, the more the users will try to find ways to avoid those measures.