no, it's just common sense.Such is the justification of every single other person in the general vicinity as well. Your short, simple answer exemplifies and proves the entire problem.
i can't hold up a motorcycle while a guy crawls out from under it. i can't overpower some thug who's attacking another woman. i can't even change a tire, for christ's sake. i know i would just be in the way if i tried to help, so the best thing that i could do in a situation like that is just get the fuck out of the way of people who can actually do something