The more health care you consume, the more you should pay. That's how it works for everything else. Now should an older person pay 500% more? I don't know enough about health care spending to answer that.
Not at all. You don't pay for your use of the roads by how much you drive, you don't pay for the military by how much you need defending, you don't pay less for our justice system if you're never going to be in court or charged with a crime, etc etc.
Minor quibble: gas taxes are intended to tie amount paid to amount of driving (and thus, road use). It's imperfect, but that's the intent.
Walt's argument extends to all facets of government, though. Your partial exception only proves the general rule.
Your taxes support all of the following, regardless of how much of each service you utilize, or whether you utilize it at all:
Public roads and highways
National security and intelligence agencies
Scientific research and development
Your local police
Your local firefighters
Clean air and water
International trade agreements
Drug and alcohol treatment programs
Long term incarceration costs
Early childhood development screening
The power grid
The international space station and interplanetary robots
The US military and all of its toys
I could go on, but so can everyone else. The point is that government exists for the express purpose of providing these services to ALL Americans, regardless of their individual need or how much they pay.
Why should basic healthcare be any different? In fact, it seems kind of dumb that we offer everyone food safety and clean water, to protect their health, and then let them die of preventable diseases just to protect corporate profits. Fuck that noise, man. Let's get this fixed.