Well, to qoute fight club, it is simply the illusion of safety at 30000 feet. In reality, and as this articld recounts, the pilots control the plane and an eggregious piloting error will not ve corrected regardless of whether I am aware that my seat cushion is bouyant, or that I should secure my own oxygenmask before helping others.

Also, I would suspect that given the element of fear and urgency in a crisis, this information no matter how valuable, will be ignored by everyobe except a mibority of overtly obedient passengers and the most measured individuals.

Tl;dr Malaysian Airlines didn't have a 100% mortality rate because no one payed attention to the onboarding safety demo.