Yes this is a big debate back and forth (how much to hold individual parents responsible vs how much of this is a systems issue) although I will say that there is plenty of precedent that "accidentally" causing someone else's death isn't an excuse legally....it's just called involuntary manslaughter. The major debate is around whether punishing these parents is having the effect we want (which would primarily be deterrence to make others think before doing something similar).
However, that isn't this case. This dude is a POS:
TUCSON, Ariz. (KVOA) — New information on the death of a two-year-old Marana girl left in a hot car.
www.kvoa.com
"One of the kids said Scholtes had left them in the car alone about 59 times in the past.
His past of leaving them in the car is supported by text messages between him and his wife Erika, one read "I told you to stop leaving them in the car, how many times have I told you."
"Investigators were able to obtain surveillance video from July 9th, the day the Scholtes’ daughter died. They determined he was at a local grocery store prior without his children with him likely left in the car, before returning to the home he stopped at a gas station, walked inside, and was seen on video entering the restroom with a case of beer, he walked out beer in hand never purchasing the items."