Well Doug, in that case, one would hope Darwinism would kick in...hopefully before said person doing stupid things has children.
I personally have not had any firsthand experience with either device, and have never even given thought to carrying one. That being said, the woods I dwell in are comparatively small; 5 miles in any direction would get you to civilization. The only place that I go hiking on any consistent basis that would be considered large tract of wilderness would be the White Mountains in NH; but, again, those are well travelled trails, and I stay on them. I am also familiar with the maps of the areas I hike, if not intimately familiar with the area itself. PLBs & SPOT devices are great for those pushing the limits, bushwhacking, or travelling over hazardous terrain; should I be doing that, I would likely rent a PLB over a SPOT. But, until then, I cannot justify spending the money on something like that, as, for me at least, it simply isnt a practical investment.