Basically, NoSQL became the big trending thing, everyone was pushing it hard simply because other people were as well. Because of this, many people used a NoSQL database when either a.) They were using the wrong technology for the problem they needed to solve or b.) They have very little/no experience with databases and working with data in general and they really screwed themselves up. Then they took to the forums and went on NoSQL crusades.

Nothing is wrong with NoSQL, used correctly and for the right purpose, it is AMAZING.