You are simultaneously arguing that it's not possible to accidentally kill everyone by having a switch be in the wrong position, and also that when this actuall

You are simultaneously arguing that it's not possible to accidentally kill everyone by having a switch be in the wrong position, and also that when this actually happens in reality it shouldn't count because "that was pilot error". Yes, it was! Those pilots should totally have put that switch in the position that doesn't kill everyone! But they didn't, and then they got too hypoxic to fix it and now everyone's dead. It's almost like there's a switch that it's a really bad idea for pilots to forget about..