Why are content management frameworks like Drupal so much more popular than MVC framework like CakePHP, but so much less fun to develop with?

Developing a website with Drupal is a process of decomposition. There is lots of stuff you need to get rid of. On the other hand, CakePHP requires a constructive mindset. You build your functionality one lego brick at a time. Now, which is the better process across various dimensions: In terms of the quality of the result, the plannability of the process, the amount of maintenance after launch etc.