You plan to solve it by compiling to css beforehand.
What if I told you I like to remove all custom css from my page. Do you have any recourse?
However, I also like saving resources and separating concerns. We have CSS to make pages look good (or at least half decent). We can make them look even better with JS, and GSS in a later version may very well do that: compile a stylesheet that does the basic layout/typography/effects and then patch what CSS cannot do with JS.
If I decide to disable CSS, I should still be able to see the HTML, and if I disable JS, I should still be able to see the content with most of the styling, except dynamic content and anything that CSS can't do.
I'll be watching GSS, a precompiled solution would be really useful.
But hey, at least with GSS there is no need to rearrange your content in weird ways to accommodate to CSS layouts. So what you'd get is just the plain, semantic HTML.
The GSS build can also be a lot smaller if we drop the three grammar parsers (VGL, VFL, and CCSS), and you pre-parse GSS to the AST in for example Grunt