When the world promotes the defense of innocent civilian life it results in the loss of innocent civilian life. The terrorists kill civilians to get press coverage; and the terrorists use human shields in order to be able to shout 'disproportionate response.' If we stopped reporting civilian deaths and if we stopped defending accusations of disproportionate response, civilian deaths would go down.
It's like the argument not to negotiate with or pay ransom to hostage takers. It just encourages them. When you don't negotiate with hostage takers you are in effect, in the short term, devaluing the human life that has been taken hostage. The argument, of course, is that the short term loss is over-ridden by the long term gain so you don't pay. Same with terror casualties and collateral damage. The civilized world's public opinion should be trained to consider them non-events, not unlike traffic accidents and people drowning in the bathtub.