I agree it would be far better if we had an environment where adults could reasonably step up in this kind of situation (i.e. defensive weapons available, with training on when and how to use them.)
But please leave the kids out of this. They don't need attacks on their character to accompany the attacks on their lives.
How can you build something up without recognizing that it needs to be built up?
I betcha that was a place where a little boy could get in trouble for pointing his finger at playmates and saying “bang, bang.” This is the excruciatingly wrong direction in which to go. Actual bullying should be cracked down on with alacrity, but this is normal play for boys. And, should they ever meet the unthinkable, perhaps what they might think to do would be a trifle more courageous. I do not blame the children for being cowards. I blame how they are taught for instilling cowardice. Far more people will be brave and bold if it is inculcated.
Also before you say lay off the kids... remember today’s kids are tomorrow’s adults. There are ways to teach them from an early age to be brave and courageous without berating them. It will take a repentant adult segment of society to initiate this.