Take control of your website! Don't be dependent on someone who just moved out of town and took all of your files with him. CMS websites made with Drupal or Wordpress give the power of administering a website back to the owner, as it should be. We know most companies don't want to build their own site but still want to update content without having to call the web designer every time.
Drupal is one of the most powerful and scalable platforms there is. And because it is open source and one of the most popular CMS platforms out there, it is always being improved by the best programers around the world.