According to some studies, ELT's have as high as a 98% failure rate when it comes to going off when they are not supposed to or, most importantly, NOT going off in a crash. Even when they do go off properly, it can take days for a search party to find a crash site. The reasons for these failures range from bad batteries to faulty wiring.
Pilots rely too much on ELTs, cell phones, and trust in their aircraft to insure their survival. Answer this: The last time you flew, did you wear footgear that would allow you to walk over rough terrain if you had to walk out? And, did you have survival gear on board to last a minimum of 72 hours?
There are thousands of documented tales about pilots who survived the crash, only to die of thirst, exposure, or their injuries simply because they had no survival training or survival gear.
Radiation. At a temperature of 50 degrees F, a 50 percent loss of body heat occurs through an exposed head and neck. At 5 degrees F, a 75 percent loss occurs in the same manner. Factor in the other four causes, Conduction, Convection, Respriation and Evaporation, then factor in not knowing how to prevent the loss of body heat in all of these areas, and you will be in serious trouble very quickly. At 35 degrees F, not properly dressed or having the knowledge to deal with the cold, your troubles will quickly include frostbite, dehydration, an inability to think or act, then in a few days, death.
If you had survival training, and had coached your family members accordingly, you would have set up a circle of rocks in your campsite with a rock at each hour point and a pointer stick laying in the middle. When your family left, they would have moved the rock closest to their hour of departure out of the circle and pointed the stick in the direction of their departure. Now you know where to start looking.
Also, if they had been trained in its use, they would have taken with them a "Save Your Fanny Pack," a minature survival kit with components in it allowing them to survive comfortably for up to 72 hours. (We teach you how to construct and use these kits.)
Oh, and no, you would not have gone bumbling around in the dark looking for them. You would have waited until morning, gotten help, then launched a search.