I think the curiosity around CM and the fact of her being a wealthy aristocrat is in part that people feel that wealth brings choices. With a more "typical" social services case, someone of low socio-economic status, their choices, if they chose to run and hide, would be extremely limited. Their access to funds, both immediately and ongoing, would likely be limited. They may not have relevant documentation like passport/driving licence, so we would think them running off to the woods, in a tent, batshit crazy but almost understandable, given their very limited options. CM on the other hand, had access to all the wealth and privilege many others don't, she had minimum of 4-5 months to put any plans into action. Yet still their actions were chaotic, disordered and ill thought out, their planning seemingly non existent. I think if drugs were a player, many would feel like, "ah that explains it", not what they did but as a reason for why they made the choices they did. As it stands there us nothing that can help to fathom why they chose to act the way they did, why they didn't plan better to take care of their "beloved" daughter.
So we end up with a devide of
A) There has to be some kind of explanation to help understand their behaviour, or
B) They're just horrible heartless (insert expletives)
While I don't wish to excuse anything they did, they are responsible for their actions and the ill fate of their poor baby, i still wish to explore possible reasons that go some way to explain their choices and help us to understand their behaviour.