I certainly hope you don't wear flip flops on the beach given they will seriously hinder your escape in event of a tsunami, which kill an awful lot more people than plane crashes. When in an earthquake affected zone do you always have a bag prepared with the recommended items you can easily get to (obviously you will know what these items are).

I have no problem with your suggestion as advice for particularly risk averse people, just the needless criticism of people's lack of foresight. People don't spend every minute of their lives preparing for the worst possible thing that could go wrong. To do so is actually very unhealthy and poses far more threat to a long life than wearing flip flops on a plane. Given how afraid people are of flying, many will not want to spend extra time actively thinking about the worst possible scenario.

You've probably never considered the Tsunami example, but it is a good way to show how ridiculous it is to suggest people are being wreckless wearing flip flops on a plane. I doubt there's even a confirmed case in the history of aviation of flip flops leading to someone being unable to escape.

Something to think about next time you condescend to others, always consider there are probably other things they know far more about that than you where they would be flabbergasted by your behaviour.

P.s I don't wear flip flops purely as I wouldn't find them comfortable, I'm just perplexed by how some people expect everyone to behave as if their plane will crash they don't do in other areas of life.