As they say "If it bleeds it leads"

Mentally you tend to equally weigh both good and bad news over a long time span, but negative news gets a much quicker and stronger initial reaction, thus it gets priority. Just an evolutionary trait, don't wait to see if the shadow is a tiger just assume it is about to attack.

This is why social media ends up the way it is, that quick reaction is what the algorithms pick up on even if long term it isn't any different. It is a hard issue to overcome especially when it is a free market race to the bottom.