The problem with what I perceive your approach to be is that when you intervene, you might not know what the situation is and you are potentially putting an innocent party at risk if you employ force to help someone.Like Ricco, that's your prerogative and I am not judging you for it. It's a free country after all and you have a right to decide what's best for you. I however, could never live with myself if someone (school kids, at risk adult or whoever) perished because of my inaction.
In your zeal to help, you might be doing more harm than good. So, turning your lofty position on its' side, I could not live with myself if I intervene on behalf of the wrong party and someone who is innocent gets harmed because of what I did.
Your heart may be in the right place, but you might want to re-think your stance on intervention.