So, just to remind you, everything was set in motion when the Mccann's left their children in unlocked accomodation, with infrequent , short checks, for several nights in a row.
Inexcusable behaviour, but you of course will never admit that, and then the question is why you never admit the McCann's did wrong.
Was it a stupid and unbelievably regrettable thing they both did, yes it was. Are they going to be haunted by their actions for the rest of their lives, I would suspect they both will. If they could, with hindsight turn back the clock I strongly suspect they would.
However, as far as I can determine, their actions were without malice or intent to harm their children. It's a tragic mistake and they paid the heaviest price any parent could pay. To compound this they can only live in hope that one day she will be found, until then for all of them, there will be no closure and that I think has to be the hardest thing any parent, regardless of their actions has to live with.
That poor choice and judgement was ten years ago and it happened, whether or not you want to lay the initial blame at her parents feet has somewhat paled to insignificance now because it has no bearing on the investigation and finding her.
If we for a moment suppose that Madeleine had been identified and was stolen to order, a committed abductor with necessary support would have grabbed her at some other point I think it's fair to postulate. We won't ever know until she is found.
When it comes to this topic I just don't see the validity of pointing fingers at her parents for the position they now find themselves in.