How is it anything like that? The parents must shoulder some of the blame, I have a 4 year old and an 18 month old, and it wouldn't even cross my mind to leave them alone asleep while I headed off for food and wine. That's just straight up negligent parenting.
Justifying the terrible action through accusing the victim.
"If she never walked home alone. If she never drank all that ale. If she never had a short skirt/led him on"
If, if, if.
"if they didn't leave the child with intermittent checks"
It's that ideology.
You can, if you wanted, blame parents for most abductions. There has to be a moment of opportunity that presented.
The action was what it was.
Should they have left children alone on their apartment with just regular checks? No. (What they did wasn't far from what Butlins used to do with their evening chalet patrol...)
But it doesn't mean they got what they had coming to them and fair game for the sick BANTZ jokes.