One of the complaints that people have about the NoSQL label is that it attempts collect a huge variety of databases that don't fit the traditional label under one name. The problem with that is illustrated in this article, which does a great job of describing problems that some of the NoSQL alternatives experience – but the problems here don't apply nearly as strongly to document-oriented databases, or to graph databases. I think the title's overstating the argument, in other words.
Now if it were "the dark side of column-oriented databases," Bob's your uncle.
Now if it were "the dark side of column-oriented databases," Bob's your uncle.