Working on the design for Spark and Drupal 8 has involved a lot of thought and research on site building in Drupal which has led me to a few interesting conclusions, one of which I want to illustrate here.
In WCM platforms there are basically two different approaches to site building; bottom up and top down. Bottom-up means basically build-it-from-scratch. That's essentially where Drupal 7 core is right now. The user must download, install, configure, choose modules and a theme, create content types, layouts, views etc.