Trying to get everyone insurance involves paying for it, which people often don't want to do.
Trying to lower the cost of health care involves working against well-funded companies willing to do anything and everything they can to preserve their profits, even if it requires destroying a few politicians along the way.
All nedical malpractice costs combined, insurance, actual payments, and legal combined, amount to 0.3% of the total cost of health care[0]. That's one-third of one percent. So its not nothing, but it's not the highest priority, either.