Drupal is a wonderful content management system. Any Drupal web developer will tell you that there seems to be a module for anything you can think of. For the most part, this is what makes Drupal so great. The community support is second to none and it's never too hard to find a module that suites your needs.
With that said, it's important to understand when there may be something other than Drupal that you should be using for a particular functionality. Commenting is the best example of this.