I think the reference is to media reports. Perhaps it would be better phrased as All that is reported is bad things. (Which is still an overgeneralization of course, but more accurate.)

Hans Rosling says we are instinctually inclined to watch for danger (aka bad news) than for safety. Ha. Makes me ask when was the last time someone pointed out a safe thing. "Watch out, that pizza in the fridge is still good."

Edit: Source for Hans Rosling: the book "Factfulness" (highly recommended—it is really a meta-discussion of how do you talk about good news with people)