Drupal and Wordpress started as blog post generators. Developers kept adding features. It's economics because it's easier and cheaper to build a REST server on

Drupal and Wordpress started as blog post generators. Developers kept adding features. It's economics because it's easier and cheaper to build a REST server on top of either one than to implement SEO and media asset management on a custom Rails or Express app. They evolved and have parts related to the original purpose stuck in the code base like an appendix. Why are comments attached to every piece of content? All that has been refactored and put in non default modules in Drupal 8 which is built with a Sinatra style router on top of Symphony.