If your application fits well into (e.g.) Drupal or Wordpress it might not make sense to reinvent those wheels.
If you're mostly trying to educate yourself Ruby or Python will be great. Building tiny sites or individual modules without a framework is educational, but, yes, generally people gravitate toward frameworks or modular systems once they need productivity.
Comments
It all depends on what you're trying to build.
If your application fits well into (e.g.) Drupal or Wordpress it might not make sense to reinvent those wheels.
If you're mostly trying to educate yourself Ruby or Python will be great. Building tiny sites or individual modules without a framework is educational, but, yes, generally people gravitate toward frameworks or modular systems once they need productivity.