Earlier quoted context omitted.
I write a lot of CSS and I would probably disagree. CSS has no console.log() for debugging, CSS often fails silently, and the demos in the link are more or less (albeit pretty neat) hacks, but don't use CSS features in the way the specifications intended.
Also no unit tests and a program model that is hard to make into a coherent mental model.
- use simplified program model and enforce it, [2]