Why did Feng Jingyao kill the Xu Wenqiang family?

Feng Jingyao killed the Xu Wenqiang family for many reasons:

1. Interests: Xu Wenqiang's actions directly touched Feng Jingyao's vital interests, because Xu Wenqiang burned the opium fields in Feng Jingyao, causing huge losses to Feng Jingyao.

2. Shut up: Xu Wenqiang has worked under Feng Jingyao for many years and knows many secrets of Feng Jingyao. As an important person in Shanghai, Feng Jingyao can't let anyone who knows his secret escape, so Xu Wenqiang must be eliminated to avoid future trouble.

3. Protect his daughter: Feng Jingyao wants to marry his daughter Feng Chengcheng to Li Ding in exchange for Li Ding's loyalty. However, Feng Chengcheng likes Xu Wenqiang, and Feng Jingyao decides to get rid of Xu Wenqiang to break her daughter's mind and protect her daughter.

4. Fear of revenge: Feng Jingyao knows Xu Wenqiang's character and personality very well, and knows that Xu Wenqiang will not let him go easily. If Xu Wenqiang retaliates in the future, Feng Jingyao will never have peace. Therefore, in order to prevent such incidents, Feng Jingyao must get rid of Xu Wenqiang.