That's fair, but I'd point out that my assumptions are no different than the assumptions that many people make about this case, their guilt, their thought process at the time, and how they'd react in a similar situation. There's also an element with this where people just want the parents to be guilty, they need to put the blame for this on someone, someone has to suffer for this, and so if even the slightest thing gets mentioned that might possibly reduce the amount of blame the parents take then they automatically default to disagreement because they refuse to accept or concede anything that might alter the outrage they have aimed towards the parents. That's an equal bias that stands in the way of objective discussion.
I agree with you that people are going to react strongly because it's a child's welfare (and rightly so), but wouldn't you agree that that's bias in itself and that's not an excuse for their behaviour - if anything it's an indication that said person needs to understand, accept and remove that (perfectly understandable) bias before an objective discussion can be had?
I'm also not giving the parents the benefit of the doubt here either, they suffer every day for what they did - I'm simply saying there are many situations where parents leave children unattended or out of sight. That's completely the truth. Some of those situations which happen every day and are considered normal are inherently less risky than leaving a child locked away somewhere out of sight/reach. If you leave your child out in your front garden playing out of sight where I can reach over the fence and snatch her, that's more dangerous than if you left her locked in your house and I had to break in to get to her yet that's a common every day occurrence and nobody is calling for parents to be sent to jail for that. The difference is like I said, people don't generally go around snatching children so it's not an issue that ever really has a discussion. People still leave children in their cars while they go into a shop for a few minutes. When you see adverts telling you not to do that, it's because of leaving them in heat not because of any danger of strangers taking them. It's easier to snatch a child in public than it is to break into a house and kidnap them. People literally walk up to children in shopping malls, take them by the hand and lead them off. It happened recently where two kids just walked up to a child in Primark and took her away whilst the mother was looking at clothes on a rack.
My mother has left me in the house alone while she's nipped out for a brief period once or twice when I was younger, and that's happened with many people that I know over their lives and many people that have concurred in this exact discussion about Maddie online that the same thing happening with them over their lives and that simply does not inherently make someone a bad parent and to suggest it does would be ludicrous that the sum of your average parents 16 or so years of parenting could be nullified, meaningless and redefined by one (the vast majority of the time) inconsequential action/mistake that in this case regrettably turned out differently. But because a childs welfare is at stake, the response is biased.
The only difference I can think of (unless you can point out where I'm wrong, which I'd be happy to concede if so) between leaving your child at home alone while you're sat a short distance away out of sight and leaving your child in the garden alone whilst you're inside the house doing chores out of sight is that leaving them at home alone behind a locked door is safer. In both examples you can't see your child, but one is locked away and the other one is out in the open. Yet there's no outrage at kids playing alone without their parents present. I can only put that down to either hypocrisy or selective outrage. I can guarantee that if a child was snatched out of a front garden whilst a parent was inside you'd see the same posts 'what kind of parent does this, what kind of parent would let their kid play in the open without keeping an eye on them' 'where were the parents, I'd never do that' even though you see it everywhere. It's 20/20 internet hindsight that you see every time 'I'd never let my kids do that' when in actual fact parents let their kids do all kinds of similar things. Sure, very few parents leave their kids alone in the house while they go eat at a restaurant at night a short distance away on holiday in Portugal, but parents do leave their kids unattended in various different kinds of situations without thinking twice and the same inherent dangers exist that are just as bad. It's only when a tragedy happens that the action is made out to be so important that noone would ever do it.
EDIT: Sorry for the post length, I really lack the ability to say what I'm trying to say in few words.