Focusing effect is a mental heuristic where
we tend to weigh attributes and factors unevenly, putting more importance on some aspects and less on others
Again from the prodigious Matt Ridley on interpreting events, (emphasis added)
Another way of making the same point is that good news tends to be gradual, incremental and barely visible, while bad news almost by definition comes in sudden, newsworthy lumps: wars, crashes, disasters, epidemics. It is impossible to see a field of wheat growing, but easy to see it washed away by a flood.