The common wisdom says that Wordpress is the best blogging platform. Why, then, should you consider using Drupal? Drupal is far more flexible than Wordpress ever thought to be. Where Wordpress only facilitates writing blog posts, Drupal not only does this, but can be extended to support flexible content types, extended to have a powerful data query and presentation subsystem, and much much much much more. If your vision is only to make simple posts, then perhaps Wordpress will be enough for you. However if your vision is to do more, then Drupal is a very worthy platform.