Developer Philip Walton:
A Rails developer isn’t considered good just because his code works to spec. This is considered baseline. Of course it must work to spec; its merit is based on other things: Is the code readable? Is it easy to change or extend? Is it decoupled from other parts of the application? Will it scale?
These questions are natural when assessing other parts of the code base, and CSS shouldn’t be any different.
I think Philip goes a bit into the deep end with his class naming conventions. Nevertheless, especially with his points about code reuse and modularity, this is essential CSS reading, one of the best articles I’ve read on the subject in weeks.