I find it odd that they didn't have more folks in the same category as myself. I would want to warn myself about the circumstances of the deaths of some people I knew. A phrase such as "Make sure he doesn't get on that bus" seems a little more important in my eyes. I suppose the warning about horrible events would have more effect, but if limited to personal experiences it would seem saving folks in your orbit would be more popular. Maybe its a sign of how much safer the world has become.
It might have to do primarily with how the question is asked. If you say "what information about the future would you impart to your past self if given the chance", then that opens it up to broadly changing future events. But "what advice would you give yourself" presents it more as what would you say to benefit yourself the most.
It's also possible that those that have had people close to them die in easily preventable ways may think of it differently. Having someone important to you die in a car crash is different than having them die of old age or of cancer or some genetic disorder, which are broadly either unchangeable, unknowable of what causes it for sure, or both.
