The British policy of salutary neglect helped contribute to the coming of the American Revolution because it made American colonists expect that the British would never enforce laws against them very strictly. When the British started to be stricter in their enforcement, the colonists were angry because they were not used to having the laws enforced.
The British government had passed various laws regulating the colonies’ trade. They generally tried to make the colonies trade only with Britain. The colonies did not like this because they felt it hurt their economies so they tried to work around the laws. Many colonists engaged in illegal trade (you could call it smuggling). During the period of salutary neglect, the British essentially turned a blind eye to the smuggling and did not enforce the laws.
The American colonists got used to this and thought that it was how things should be. After the French and Indian War, however, Britain started to enforce the laws more stringently because it wanted to make more money off the colonies to help pay the expenses from the war. Because the colonists were used to being allowed to break the law, they felt it was unfair when the British started to enforce the laws.
So, we can say that the policy of benign neglect helped lead to the Revolution because it created a situation where the colonists became very angry when Britain enforced laws that had existed for a long time.