When you step foot into the backcountry, you step out of civilization. By definition, the backcountry is wild. We maintain and preserve the wilderness FROM OURSELVES. The danger as well as the risks are implied.
That being said, if you step out onto train tracks and get hit by a train, is it the fault of the railroad for lack of notification stating that a train may pass through and hit you? Or is it the individual (in this case the parents of the victim) that is neglectful of the risks involved? It matters little if that train had previously ran over anyone because the risk is implied.
Do you swim in the ocean after shark attacks occur? If you swim in the ocean you do. What about the Florida coast that sees more attacks than most? Who is at fault of another attack? Is the ocean not wild?
Whist's next? Sign a waiver before you have a swim? Before you head into the backcountry? Before you cross train tracks? This is ridiculous.
**edit: any time there is a loss of life it is tragic. I am sorrowful for their lost. My questioning regarding the ruling is where the burden of responsibility lies and where that line is. We live in a litigious society where blame is usually placed not on ones self. At some point, we have to start being responsible for our own actions. The family did not demonstrate an ounce of backcountry knowledge and did not take the proper precautions. The only fault (imho) is the ranger's belief that those entering the backcountry do so having taken the proper steps to ensure their safety and the safety of their loved ones.

