Comment by yamrzou

Chronic procrastination can be associated with perfectionism, in which case it is the result of fear of failure because of the self-imposed high standards. The reason for the fear of failure is that the failure is perceived as the individual failing to measure up to their ideal self, which threatens their self-worth.

So procrastination is a defense mechanism, but it is a maladaptive one, because the individual ends up feeling ashamed of their procrastination.