If a system uses all of the knowledge that it has, it must be perfectly intelligent. There is nothing that anything called intelligence can do to produce more effective performance. If all the knowledge that a system has is brought to bear in the service of its goals, the behavior must correspond to what perfect intelligence produces. If a system does not have some knowledge, failure to use it cannot be a failure of intelligence.
Intelligence can work only with the knowledge the system has.
If a system has some knowledge and fails to use it, then there is certainly a failure of some internal ability. Something within the system did not permit it to make use of the knowledge in the service of one of its own goals, that is, in its own interests. Intelligence as defined is not a measure, but a description of adequacy over the range of two complex domains, the system's goals and the system's knowledge. Can't improve upon innate. Dis-ease due to interference with innate flow.