Certainly, everything has trade-offs, but CSS pre-processors are more heavily weighted toward the positive side of the trade-off calculation than pretty much anything else I can think of, especially in the "web technologies" space. I found lots of the arguments in the OP to ring true – things often feel far too fancy, and the more "boring" stuff has major appeal – but I found the arguments against CSS pre-processors there and in the article you linked very thin relative to my experience with them after years of using raw CSS.