Nail on the head.
Were Americans required to pay 100% for routine doctor visits and checkups, health insurance would be much lower. People would not go running to the doctor for every little sniffle or stub on the toe. People would not be looking for "painkillers" every time they sprang their ankle or anti-depressants for when they broke up with their boyfriend.
It's easy to clog up the system with non-necessary visits when there is only a $10 co-pay to see a doctor or $5 for a bottle of pills.
Health insurance should only kick in for a catastrophic situation like cancer, heart attack or serious car accident.
People keep up with oil changes and tuneups on their cars because they want to avoid costly repairs down the road that are not covered by their insurance. People would have the same attitude about their bodies and would take care of themselves better if they had to pay the full bill.
Ever look at car tires in the big box store parking lots? Many don't keep up with routine tire maintenance? Those people aren't going to pay $500 for a routine office visit and blood work if nothing is going on with their health.