Every system entails rationing.
In a private system, your resources and your choices determine how decisions are made.
In a "public" system, govt decides. Yup - they'll take resources that you might have used for for your care and spend it on someone else and deny you care.
We already hear "we're not going to pay to care for fatties or smokers". If they're not going to get care, I think that it's wrong to take their money. That's just me.