I would imagine the commenter was referring to the works of Rand. Google for some of his corporate brands and look at all the black. Try the Next logo for example.
People here also seems to take it far too literally. There are always exceptions, no matter how absolute the article words it.
But while rules are there to be broken, they are best broken when you are skilled enough to know when it works to do so.
Most people who will read that article are not going to be skilled enough at graphical design to be able to easily decide when breaking this "rule" is an improvement and when it makes things worse, and so will probably benefit from paying attention to it.
Those that do understand when breaking it is really an improvement should go ahead and do so when appropriate.
The problem of course is that far too many people think they're experts.
