In the old days those who were prone to anxiety, stress and depression were less likely to get eaten by lions than were the cheery, rose-tinted optimists. So the morose had more children and morosity mushroomed. Paranoia is in our genes for a reason.
So, let us put our hands together for the mutterings of the moaning morose. They are the bright hopes for the future. Or, if that seems over the top, then let us at least give them credit for being critical of and resistant to the status quo. As R D Laing (more or less) noted, in an insane world the truly sane are labelled as nutters.