(responding to the bolded part)
Respectfully, some of us are wondering whether this assertion is actually true (unless by "safe" you mean alive). I myself have an almost automatic urge to say "well, of course they only wanted the best, of course they thought it was safe" but that's only because that's what I want for MY baby and I cannot imagine thinking any other way.
The problem comes in when we try to apply that sentiment, that "of course they thought it was safe" to what we know they actually did. That's where it just falls apart. No, that's where it freaking implodes.
Do any of these sound plausible?
"
I thought it was safe for my three daughters to play with the power saw."
"
I thought it was safe for my three daughters to hitchhike to Cleveland.."
"
I thought it was safe for my three daughters to move in with the strange single man down the street."
Giving people the benefit of the doubt is a noble thing, but not when doing so demands the sacrifice of objective reason. In my opinion, that's where we are at when talking about the motivations of the parents in this case.