2016 has to been seen in perspective. It is not so much the nature of the events that have occurred, but the fact that there has been a loss of consensus. The General Election in the United States, and the United Kingdom's Referendum on the European Union both left almost 50% of the electorate unhappy.
The truth is that it is foreboding for the future that weighs heavily on people's minds. It is not so much that 2016 was bad, it's that it has left so much uncertainty about the future.
RE: Why 2016 Was The Worst, Most Horrible Year Ever