Perhaps root is too powerful, and Unix should have finer-grained capabilities or ACLs (Access Control Lists) for system-administration functions, rather than one superuser that can do anything. People who take this position argue that too many system programs have permanent root privileges through the set-user-ID mechanism; if even one can be compromised, intrusions everywhere will follow.

This argument is weak, however. Modern Unixes allow any given user account to belong to multiple security groups. Through use of the execute-permission and set-group-ID bits on program executables, each group can in effect function as an ACL for files or programs.

This theoretical possibility is very little used, however, suggesting that the demand for ACLs is much less in practice than it is in theory.