Because default WordPress user registration and login is NO GOOD for modern websites.

Do YOU want to customize your website by adding front-end registration, profile and login forms? You can use Profile Builder - the Profile Plugin for WordPress.

To achieve this, just create a new page, and give it an intuitive name (i.e. Edit Profile). Now all you need to do is add the following shortcode: [wppb-edit-profile]. Publish your page and you are done!