Please read Håkon Wium Lie's PhD thesis http://people.opera.com/howcome/2006/phd/ to understand the reasoning behind the development of CSS. I think it was going in the right direction, although the ride got bumpy when committees and commercial interests started getting involved. Its major objective was to achieve separation of content from presentation which it achieved and I think you being unfair in your statement about CSS not being great for its original use case.

CSS did borrow concepts from TeX at the time. I agree with you that if it had borrowed more from TeX maybe we would have avoided Javascript and also we would have benefited from an updated model for TeX and I said so at http://tex.stackexchange.com/a/6463/963.

Maybe is time to revisit and revamp both.