why was this a crime?

There is a heartbreaking article in the Washington Post by Gene Weingarten on a child that was accidentally left in a hot car and died. This and other horrible accidents happen with children every year and he reminds us that it could have been us. When this story came out there was a lot of ugliness by people saying things like the mother should be locked up and forgotten or she doesn't deserve to live. I so agree with his explanation below of people's hate-filled and judgmental comments.

 "If the ugliness seems puzzling to you, it doesn't to psychologists who have examined this phenomenon. It’s a form of denial, they say: Deep down, people understand that all lives are fragile, that we are all capable of momentary mistakes or misjudgments that could destroy us. We don’t want to face this terrifying fact. So we must convince ourselves that the people to whom it happens are unlike us. To sustain our delusion of safety, we must make them monsters."