Why isn't Drupal aggregator configurable? I am trying to display the RSS feed of this page: http://groups.yahoo.com/group/actventurers/, on a drupal website.  

I have the aggregator module enabled, but when I go to /admin/config/services, only RSS Publishing is available.

Any ideas as to why it won't allow me to add any feeds?
Use Feeds, it's import or aggregate RSS/Atom feeds to Drupal.