That is a myth. I used to work for the city-council of Amsterdam and studied the yearly figures; the people that are most likely to be a victim of violence are young males in there teens and early twenties. Young, aggressive, dominant men who have an urge to prove something. Hormone-driven they will always find a reason to pick a fight with another young man with the same attitude.
These figures have been compared to figures in other cities all over the world. Same results everywhere.
It is not possible to compare it with predators in nature who try to cut out one animal out of a herd. But even if we would want to make that comparison; it is not true that it is always the weak that gets cut out. Many times it is the weak (the young) that are best protected.
Funny thing is; I usually get to hear this "weak frail old lady that gets raped, mugged and murdered" myth from people who are training martial arts. Is saving such an elderly lady an archetypical phantasy for everyone who is into martial arts?
One of the inspiring notions of being in balance with heaven and earth as we stand on the heavenly floating bridge is that there is no longer a need for anyone to attack us. That seems to me a form of strength or power that is worth working towards.
Violent crime in general, yes - but the elderly are more
likely to be victims of violent crime by strangers, according to the US Department of Justice statistics.
None of which matters - you pointed out yourself that young people are more likely to put themselves in a situation where such a thing will occur, and the fact that someone else gets attacked too doesn't eliminate the problem for the elderly.
The point is - there is no inherent protection in appearing frail and weak. The discussion had nothing to do about "fantasies of saving an elderly lady", which wasn't even mentioned until you brought it up - I suggest that you go back and read the thread.
Being at a point where there is no need for anyone to attack us (although I question whether such a point can actually be reached) is all well and good, but that's not what I'm talking about here.
The Floating Bridge of Heaven
as described by Ueshiba really has nothing to do with "being in balance with Heaven and Earth" in that sense. He is describing a training methodology, a very old one, and one that has to do with martial application.