Actually, I think you've got something interesting mixed into that comparison: assembler. SASS/HAML aren't like a high-level programming language like C or Ruby, because there's really just not that much translation going on. They're more like assembler: a one-to-one mapping of machine language that makes it easier to read and work with.
Sass (not Haml) allows you to work at a significantly higher level than CSS. The parallel in programming languages might be Forth: the basics translate directly, but using the abstractions provided by the language you can make it work at a much higher level.
In the case of Sass, abstraction is primarily provided by mixins and functions. Compass (http://compass-style.org) provides an excellent example of using these to write CSS at a much higher level.
