If I have GOOD genes, and am not likely to end up with cancer, heart disease or other expensive types of medical conditions, why should I be required to pay the same rate for insurance as those who have a high likleyhood of getting such diseases?
Insurance is about probability and risk. Insurance companies pool a bunch of people together, determine the risk of a particular disease and calculate how much it will cost, then decide how much to add to the price of insurance to cover people for the disease. They are covering their risk.
It's the same with auto insurance. Mature, careful drivers are not charged as much for insurance as are immature or careless drivers. People who have been arrested for drunk driving are considered to be very high risk drivers and as such their insurance rates are very expensive. Do you think that careful drivers should pay as much as careless drivers? Careful drivers don't think so, just as people with healthy ancestors don't generally think that lower medical and life insurance rates are a bad idea if we aren't likely to get a disease.