[valbis]

Needing a full feature programming language for things purely related to the page aesthetic is not a great idea.

The reasoning: some hosting platforms allow you to personalize your personal page changing the HTML and CSS bits, but not the JS - for security reason, obviously. Itch.io is an exmaple of that, where you can personalize your game and profile. By using CSS animations I can create cool effects without any of the security concern that allowing access to JS gives me. It makes sense and it's nice to be able to do so.

[Cthulhu_]

Counterpoint; anywhere but the web, using the same application programming language to define styling and visuals is normal. I get your point though, JS is still an all-or-nothing thing in most use cases.