Felicity Evans writes a “manifesto” for well written Sass in A List Apart:
Yet alongside the wide-scale adoption of Sass (which I applaud), I’ve observed a steady decline in the quality of outputted CSS (which I bemoan). It makes sense: Sass introduces a layer of abstraction between the author and the stylesheets. But we need a way to translate the web standards—that we fought so hard for—into this new environment. The problem is, the Sass specification is expanding so much that any set of standards would require constant revision. Instead, what we need is a charter—one that sits outside Sass, yet informs the way we code.