As I reread the thread, even though the title specifies "AVIATION SURVIVAL KITS", I think your main gripe/rant is with the hazards of small General Aviation (GA) aircraft and not with survival kits per-say. The survival kit I have is not for GA flights; when I fly, 90%+ is IFR over water. Some flights it's 99.9% over water.

That said, if I was to go for a joy ride in a Cessna 172 I'd definitely take the vest whether or not I was feet wet or feet dry.