Django CMS project is a large and complex project, comparable to Wordpress. As such, it may be too much for a simple personal blog considering that it has many features that may never be used in that particular occasion.
WP has grown past being just a blogging platform and as such it's not as lightweight as it used to be. It also considerably more complex due to many more customization options compared to other solutions.
Drupal can be customized to do almost anything. It was built ground up with the intent of using a wide variety of small modules to get the exact result wanted instead of just the most common solutions.
Drupal is not easy to get into and out of the box doesn't offer much. To get Drupal doing what you want it to, modules are required. To get modules, an understanding of how Drupal works is required. And that takes time.
Keystone comes with an auto-generated Admin UI, which makes things very easy for any task that can be completed using Keystone. In any way Keystone is used, the Admin interfaces saves a lot of time and makes any job easier.
Although registering a new user is very easy, there is not any roles system out-of-the-box. There is only a check box "Access keystone" which gives a user full administrative power. Adding different kind of users is only possible by editing the user data model.
MongoDB is required to be up and running and a Yeoman generator is used to generate the application. Although the prompt based start-up in the command line helps you a lot, it still can be hard for someone inexperienced with NPM and Yeoman.