Interesting article.
It actually surprises me how few cases there are, and how few of those involve drugs or alcohol, which would seem like the most likely factor if this was merely an issue of not paying attention or having the capacity to care about anything.
It seems to break down to women without a babysitter who go to work/get hair done etc. and are "too stupid" to know how dangerous it is, and people on 'autopilot' hyperthinking about something else.
If these women were so reckless and uncaring, it would make more sense to leave the kids at home or running around the parking lot, versus certain death. I really do believe they were too stupid to realize their children would die a painful death. They may not have been super responsible, but I still don't think they had any idea of the danger.
I think the idea of punishing them through community service that involves going around speaking to new parents is a good one. I really believe this is an ignorance issue, and jailing these people doesn't act as a deterrent because people don't watch the news. A lot of people need to be explicitly told this - particularly people who maybe did not grow up in a household with a car (particularly pre-air conditioners) and didn't experience how insanely hot a car can get.
It's definitely hard to believe the 'autopilot' thing - but there really aren't many of these cases, because it takes such a specific set of mental circumstances to cause such a narrow view. If parents manage not to do this 300 times, and then do it the one time, and there's no reason to think they would want to kill their child, I think it is just a freak accident. Humans aren't wired to be dropping off a child and moving on for 8 hours of hard work every day - switching focus like that isn't easy. Modern life has too many different mental modes, and I think it can really screw people up. Leaving a child for 7 hours and not realizing it is quite disturbing, but I can see how they feel like they dropped the child at daycare when they do it so frequently. It's all so horrifying.