Lots of people without kids do not understand although some do without children but theres a reason why many do not.
This line of thinking is stupid though.
Why does a child have more value than a productive member of society? What makes them so special that they would avoid a necromorph outbreak?
It make sense from a reality point of view in both Dante's Inferno and Dead Space that children too would become victims, especially considering the nature of the stories.
I'm glad both games have children, because it puts a realistic and mature theme into the games that would otherwise be like other games that avoid the realistic probabilities those situations would have.
But again, what makes a child more valuable than the average Joe blow in a game? Is that child's life somehow worth more than an adults? They should be just as susceptible the the horrors as anyone else, and skirting the issue is sad.