I was unaware the product existed prior to this thread, the reactions are interesting but hardly unique. I've had any number of dangerous hobbies and whenever there is a simple product, the experienced reaction is generally along the "Your training should have xxx" so it's dumb. Even for items that literally do nothing bad, and under very specific circumstances do good. It's true that in a perfect world no one dies from stupid things that they should know better about. But one of the common saying in training for my last career was "Complacency kills."
When you have done a million traffic stops, it's easy to expect a million and 1 to go just like the others. But that's the 1 that kills you. You've been to the same house for the same problem and had the same conversation a million times. And today, you die. When you have a long streak of everything going right, it does get hard to remember that it doesn't always go that way.
I used to jump out of planes. Know who dies doing that? Not the new guy. The guy with a thousand jumps does a low alt hook turn, and he dies. He knows better, but he does it anyway, and now he's dead.
I used to fly planes. Know who goes down because he skimped the pre-check? Not the guy who just got his license.
I used to rock climb. Know who forgets to actually clip into the rope? Not the new guy. It's the guy who's been on the rocks a billion times, and done a billion raps, and he doesn't actually run the rope through his ATC before he leans back. And he's dead.
Almost all of my hobbies have exactly 2 rankings. There is grand champion, and stuff on a rock. Newbies are ALWAYS grand champions. So far I've retired from so many dangerous things and maintained my GC rating that I've lost count. And it's by constantly combating complacency that lets me take up my new dangerous hobby. If I'm about to do something stupid and someone tells me "Hey, you're about to die" I'm grateful. The entire buddy check is nothing but a person keeping you alive, a product that does nothing but allow a 3rd (or 4th or 5th etc) see that you missed something simple isn't IMO a bad product. But that's just me.