Heh, obviously you've never used Tumblr before. Tons of people that I follow learn basic HTML and CSS by customizing their blog's theme, and the end result is insanely creative and unique blog layouts.
Not only that, but a lot of the content they're posting is original and creative as well. Whether it's original art, stories, poems, collages of gifs from a favorite TV show, etc, it's extremely easy (in my experience) to find creativity on Tumblr.
Your comment doesn't add to the discussion and is simply inaccurate.
You are still working around rules and a framework.
Geocities gave you free run of HTML & JS to go nuts.
For example: Geocities accidently gave me my first experience designing backend as a service when I was a teenager.
I had built a website using some PHP but I had a budget of ~$0 for hosting and I couldn't find any free PHP webhosting that also offered mysql and didn't have extremely stringent bandwidth restrictions (I wanted to allow downloads of some fairly large .exes for VB6 games I had made) I used my home internet connection for playing online games so I didn't want people downloading files from that either.
My solution was to host all of the files and the front end of the site on geocities (which had a much better bandwidth limit but didn't support PHP) and redirect all of the POST forms to a Pentium2 linux box running off my home internet connection (with dyndns to take care of the dynamic IP issue). The form submission would sometimes (if it needed to update the site frontend) kick off a script which would FTP the new content to geocities. It could then just redirect you back to geocities once the form submission was done.
