The only reason Wordpress and Drupal became successful is because PHP is present on basically every shared host you can find on the internet. They stayed succes

The only reason Wordpress and Drupal became successful is because PHP is present on basically every shared host you can find on the internet. They stayed successful by building a community of plugins and themes. The actual internals of both are a complete mess, and trying to get them to do anything outside of trivial blog hosting and content management is a nightmare. Just because you don't know of any Python/Ruby/Java "apps" doesn't mean they don't exist. Jenkins, Redmine, Trac, etc.