A lot is said about LESS and Sass, and for good reason. CSS is hell to get right and even harder to maintain. LESS and Sass (and similar tools) make CSS into a much more useful language.
But when people talk about why they are so great, they miss the main point. It is true that your style files are now shorter and more readable. However, there is something deeper going on than mere saving of keystrokes and being able to name things.
In this essay, I will try to put into words (and some pictures) what my intuition tells me as a developer and programming language enthusiast to clarify why CSS is innately unmaintainable, does not satisfy its own design goals, and why LESS and Sass make a bad language more bearable. I also will propose solutions which would raise the bar past the high level where LESS and Sass have taken it.