    (h1 :disabled Hello world!)
    (div :class="alert"
          So long, and (b thanks) for all the (em fish))

I hate that syntax for attributes.

:class="alert" is strictly worse than ((class . "alert")) or any other variation that actually leverages s-expressions instead of merging key and value into the same symbol. Ew.

Not a fan of the bare words instead of strings either, which means this cannot be naively evaluated by a Lisp.

I wouldn't say this is producing html from s-exps, rather that it is vaguely inspired by them.