Photographs like that aren't sought out and taken just for the sake of a competition. They get taken because the subjects matter to the photographer and the photographer wanted to take a picture of it/them. It just so happens he's a journo and submitted it later which won him a competition.
Besides, without images like that people would not bat two eyelids when it comes to bringing 3rd world issues to light. A good picture stands a far better chance at people taking action than a rubbish one. Just the way it is.
I think the point is that carter didn't take action himself first, but rather do his job and sat there for 20 or so mins to get the photo then take action.
Would people sit there and wait 20 mins, if they saw another human in pain just to take a photo before helping, I know I couldn't. If we all help a little the world would be a better place.