I boils down to the level of Empathy one has.
Empathy is a scale, not an absolute, and plenty of people who do have some Empathy can switch off the little they have easily enough, whilst some can't or, if they do, doesn't last long.
If you look around you can sorta see that people can be roughly divided into three groups, a minority who are really good people who care for others and help them out for no gain for themselves (sometimes even at a loss for themselves), another minority that couldn't give a rats ass about others and are willing to destroy other people's lives if they themselves personally benefit from it (sometimes in petty ways, such as just the feeling of being powerful) and the majority who are in the middle and just float towards whatever they perceive is the main mode of being of the time and place they're living in, which in America now is Selfish Individualism, or in other words, being a lot like the second group who has no Empathy.
So yeah, you'll always find individuals who won't bat an eye at doing this, and in the right time and place most people will be in practice living with their empathy switched off hence will look at this and feel nothing (because they won't empathize with the children at all), and at the same time as the other poster pointed out some people find it impossible not to look at this and feel disgust and even rage because they can't switch their empathy of, or at least not for long.