I guess, every CMS has same problem. Either you build from scratch or use one of the CMS. For quickly setting up a web site Drupal/Wordpress is good option. There are plenty of cases, you would not want to write from scratch. For example, I am running my website on Drupal(http://www.avabodh.com) without writing any code. I do not have time to write code for my website. My requirements are very simple. It will be waste of time if write CMS from scratch for my purpose. I dont think there exists a good replacement of Drupal today.