Here are some reasons (might overlap) why voters vote for dynastic rulers:
Here are some of the things that I feel are necessary to help voters pick the right candidate. Some of the things seem impossible, but well, a start can be made:
Family members are surrounded by sycophants and to hell with democratic values
Why should party members help perpetuate the dynasty?
Here are some things that can be done to prevent dynasties, again seems impossible in the present scenario:
What’s wrong with a dynasty if the person has “merit?