The Houdini APIs are not really about "JS in CSS". They are about extending CSS features (like adding new features to CSS, new keywords or what have you) by providing a JS implementation at runtime.
OK, good point! And neat demo, thanks! I guess if you can add features to CSS, you can add a feature to have evaluatable JS! And that is a pretty neat demo.
It is not the main targeted use case of Houdini though! (And I'm gonna go out on a limb and say the Houdini devs would say it's a bad idea as more than a cool toy!)
