Why is system performance configuration removed upon uninstall?

I see that in regcode_simple_uninstall() the system performance configuration is removed:

/**
 * Implements hook_uninstall().
 */
function regcode_simple_uninstall() {
  \Drupal::service('config.factory')
    ->getEditable('system.performance')
    ->delete();
}

What's the reason for this? I don't see any other references to 'system.performance' in the module. Is this is a mistake?