True tho, I was like, isn't it's unfair if you don't get even a tiny chance to , like prolly change yourself in a good way. In this case what I saw through Hu Gong action was like he simply gave the kids a tiny opportunity or an option to change their selves. But after became a grown-ass man/woman, they still, I would say on the wrong path (which is bringing so much destruction) and they deserve to die bcs they ignored or like turn a blind eye to the opportunity given, or more like, they was too driven by the unnecessary grudges. Simpler terms, I would say, Hu Gong is a nice person, but to kill the kids was so wrong, sooooo to justify the killings act, he just wait for them to grow up. But I'm sure he would not kill the kids if they're on the right path.
some of the ppl in here really sayin "oh I'd kill the kids" which is INSANE btw. the reason why he never did is because he KNOWS that's wrong and he's basically raised his friend's kids and his own disciple. Kids aren't inherently bad, it's the environment or the adult that'll groom them to be that way