Fifteen people blown up in China or 20 drowned during the monsoon in Bangladesh means nothing (to other than family and friends) and has little if any meaning half a world away.
Maybe. There are lots of dreadful events that involve small numbers (e.g. a couple of dozen) that still move - such as bombed mosques. The shots of children in hospital with missing limbs, or a mother wailing over the loss of her family, are always hard to watch.
Precisely. It's "sanctioned", almost prurient, voyeurism, like rubbernecking at gruesome accidents. Who needs it?!
And 'being meaningful' doesn't have to involve death. I remember how ticked off I was with the visual reports of ISIS destroying ancient artifacts and centuries-old buildings. In those cases, nobody was killed.
And before that the Talaban.