Create post for every user?

Create this as a plugin and activate it. It deactivates itself after it creates a primary page for Authors and sub-pages for each Author+ or better Role. At the end, it deactivates itself.

Improve it as you wish. It uses

// Hook activation to create new Author Pages
register_activation_hook(__FILE__, function(){
    // Create a Parent Page for all Author Pages
    if(!($parent = get_page_by_title('Authors'))){
        $parent = wp_insert_post(array(
            'post_type' => 'page',
            'post_title' => 'Authors',
            'post_content' => 'Authors are children of this page.',
            'post_status' => 'draft', // Or publish
        ));
    }
    if(!$parent){
        // Bad... ERROR!
        return;
    }
    // Get user IDs, get_users() returns too much data
    global $wpdb;
    $IDs = $wpdb->get_col("SELECT `ID` FROM {$wpdb->users} ORDER BY `user_registered` DESC;");
    // Loop IDs and create subpages for Authors+ (not Subscribers)
    foreach($IDs as $ID){
        // Get user
        $user = new WP_User($ID);
        // Only create pages for Authors!
        if(!$user->has_cap('edit_posts')) continue;
        // Create page for Author
        $title = "About Author: {$user->display_name}";
        if(!($child = get_page_by_title($title))){
            $child = wp_insert_post(array(
                'post_type' => 'page',
                'post_title' => $title,
                'post_name' => $user->display_name,
                'post_content' => 'Write stuff about the Author.',
                'post_status' => 'draft', // Or publish
                'post_parent' => $parent,
            ));
            // Setup according Metas (for further tracking)
            update_post_meta($child, 'about_author', $user->user_login);
            update_post_meta($child, 'about_author_ID', $user->ID);
        }
    }
    // Done! WILL RUN JUST ONCE, deactivates itself afterwards.
    deactivate_plugins(__FILE__, true);
    die;
});

It’s kind of a hacky approach but will do what you need. It uses a PHP 5.3 Closure. Consider reverting to PHP 5.2 compatibility an assignment 🙂

Regards.