Yes, of course... and you probably shouldn't drive at 2 am on a Friday night with children in the car, unless it's not easily avoided.
But you can only do so much. Everything is a calculated risk.
And there are plenty of ways to take children into the outdoors without taking the risk these parents did. There are thousands of miles of hiking trails in California alone that are not as remote and don't lack cell service as this location. That's my entire point.
I think if you look at it as "everything is a calculated risk," you'd find that the only way you'd rationally consider this any riskier that various other things they could have chosen for their weekend activity (such as a road trip) was through the 20-20 hindsight that is conveniently available to you.
Since we don't even know how what caused their deaths, it's quite premature to blame the parents for doing something risky.
But you can only do so much. Everything is a calculated risk.
And there are plenty of ways to take children into the outdoors without taking the risk these parents did. There are thousands of miles of hiking trails in California alone that are not as remote and don't lack cell service as this location. That's my entire point.