Answer:
American citizens are humans which means that they have different skills and competencies. This means that even though they have the right as citizens to join the government as civil servants, it is imperative that they join the service in a manner that would be most beneficial to the country. This is why Civil Service exams are important. They gauge the skills of the applicants to determine if they would be good fits for the service they would like to join. For example, Shannon is no good at math and financials but applies to the Securities and Exchange Commission (SEC). If there were no civil service exams to test his competence, he might be hired and put in a position he would not be able to contribute to the government's efforts effectively.