Good people are rare because it is very hard to be a good person. Ming Xia. To be a good person requires a lot of tolerance and it is extremely difficult to endure.
Ming Xia already has the power to bully the girl who made her life miserable for three years, who made everything so difficult and also added to her stress but when Ming Xia had that power, she decided to let it go.
What does this mean?
Does it mean that Ming Xia doesn't have the audacity to bully Li Ai? Does it mean that Ming Xia was scared of Li Ai? Perhaps, Ming Xia was too weak-hearted and she couldn't get her revenge.
No, Ming Xia simply just wasn't Li Ai. Ming Xia was Ming Xia and she wanted things her way. Being like Li Ai who had bullied her would only belittle her and there would be no difference between Li Ai and Ming Xia if Ming Xia chose to bully Li Ai for everything she had done to her.