Feelings need a common entrance to express.
Arguments need a common exit to end.
Communications have to be clear for understanding each other.
If both sides insist on a detail, a specific condition, a limited micro level, there are always exceptions to fire debate.
So, I prefer analogy with something ordinary:
#1 The farmer
"… teacher Liu praised his new student for her first report, and criticized others for doing worse than a newbie. Everyone feels bad …"
"The true problem is that a teacher like a farmer, the new student like a tree grows well in her former farmer's hands, her fruits don't belong to the later. Teacher Liu should reflect on his farming system instead of losing temper. "
#2 Go to see a doctor
"Everyone's life is not easy. There are hurts and they could be healed with self-power. It's okay to leave them alone."
"Why there are doctors? You have to be told you have cancer or just a cold. The true sick couldn't be healed by tolerance. Only after being checked in the right way, your self-power could work in the right way. "
#3 Disappearing forest
"Why unhappy? Not all efforts would get paid, busy for nothing, that's life. "
"Blind busy? No pay? I have been working hard to cut trees down, and never questioned myself why. You can see I didn't get the reward for a wooden house or wooden board, but I successfully turn my lively forest into dead desert. Tomorrows will pay for everything you've done."