wp_delete_user() fails during a wordpress scheduled job

I have a plugin that deletes all users from a WordPress installation. The plugin registers a new menu page and when a button is clicked it deletes the users. Here is my code:

$blogusers = get_users('blog_id=' . $GLOBALS['blog_id'] . '&orderby=nicename');
foreach ($blogusers as $userToDelete) {
   wp_delete_user((integer)$userToDelete->ID);
   }
}

The above deletes all of the users (except admin) no problem. However, when I put the code into a hook and schedule it, if fails on the first wp_delete_user() code.

wp_schedule_single_event( time() + 1, 'hook_name' );

Any reason why you can’t make that call within a scheduled job but it runs fine outside of one?

Thanks!