Hmm... The cancer argument seems a little off the mark to me.
Statistically, we're all quite likely to die of pneumonia. However, we're very unlikely to die young of pneumonia, or even kill a loved one, as we are in aviation. 'Cancer', whatever that is, is a slightly more complicated question, but it's still true that it doesn't hit most people until they're reasonably old, and eating sensibly and not smoking are far better ideas than most (but not all) screening programmes.
So back to worrying about twins, ditchings and things we have some influence over. There are a lot of ways of dying in aviation, even if individual ones are reasonably uncommon, so in my book it does make sense to discuss them.
My respects and thoughts are with the family of the gentleman who died. I hope it doesn't come over as disrespectful to discuss the accidents.