Americans are sticklers for punctuality. Of course, this is not true of every person in every business in the United States. However, it is generally true. American businesspeople do not approve of, or have a high tolerance for, people being late. This is true of things like business meetings and it is true of job interviews.
To Americans, punctuality is generally seen as a sign of virtue and reliability. When a person says that they will be at a certain place at a certain time, it is important to be there at that time so as to maintain one’s credibility and reputation. People who do not show up on time will be seen as untrustworthy. Others will think that they are not sufficiently dedicated to their jobs to make them worthy of trust.
In the American business world, it is vital to be punctual. People who are not punctual are not seen as the kind of people who should be hired, promoted, or bought from. Therefore, a person who is habitually unable to be punctual will not get ahead in the business context.