The linked piece in this article pretty well explains the problem. Their graveyard has many children and babies in it that basic medical care would have saved.
It states this proposed law would not apply to anyone of legal age. If an adult in the eyes of the law wants to shun medical care that’s their decision, but not kids.
For absolute physician shunners like this, it’s easy to be unsympathetic to them. I’m concerned about mission and precedent creep into other areas of child raising that don’t entail unreasonable risks of harm.