I am not supporting their ignorance. But I imagine their belief arose from some deep issue with human agency. ie the apparent arrogance of trying to control natural forces, which would have been ascribed to the Divine, just one or two generations ago.

Nevertheless, I take issue with your edit. I believe your wish is in fact rooted in your own desire for agency. Those parents have lost a child, albeit from their own ignorance. In light of this, how do you think their prosecution would be a gain to society? We can surely educate others without inflicting even more damage on those poor, grieving parents.

Doesn't this whole argument hinge on the notion that children don't have a right to life/medical care outside of the context of the agency of their parents?

If they do, doesn't it follow that parents denying appropriate medical care to their children (on whatever grounds) is tortiously negligent and therefore ought to be prosecuted?

"We can surely educate others without inflicting even more damage on those poor, grieving parents."

On the contrary, I think we should make an example of people like this. The penalty for doing something like this really ought to be high enough to dis-incentivize people from carrying out these kinds of actions based on their idiotic beliefs.

I can scarcely imagine the pain of losing a child and knowing that it was due to my negligence. Do you seriously think that, on top of all this suffering, the risk of a custodial sentence would add further disincentive?

I am not arguing that these parents were not idiotic, just that their further punishment can serve no purpose.

We may have to agree to disagree though.

I mean, for the parents in question the ship has already sailed. I don't think it's a bad idea for parents who are engaged in clearly negligent behavior to be prosecuted (hopefully before something like this happens.)