It's also for more backwards compatibility, though <figure> and <figcaption> is going to stay, because those make a lot of sense.
Coming up next: out with JSON-LD. It was an interesting experiment which didn't bring any good at all, even in the long run.
becase it's easy to write, forces me to use some sort of structure, and it might come handy.
However, the end HTML is microformats v1 and v2 - v1 for google, search engines, etc, v2 for anything indieweb.
While Pandoc was generating something sane, the output of CodeHilite puts silly amount of extra text and makes the HTML output completely unreadable.
In the end, it still looks like prism.js is a nice and solid solution, even if it's JS.
I'll explore other options, but so far, it's either back to Pandoc, or sticking with Prism.