The rich may leech off the system, but so do the poor. I see examples of it nearly every day. Which is why there shouldn't be any system to leech off of. Not abolishment of government completely, but certainly downsizing it from the ridiculous bloat it has become. No welfare or loopholes for anyone, rich or poor, to use.
The poor don't ask for Trillions They Already Have, however.
Also, here's a cool chart from Moody's, showing the estimated return rates on investment in social programs; many of those you lash out against have POSITIVE returns (if you're wondering how, it's mostly to do with enabling workers and businesses to continue working or have infrastructure):

I am fine with my return off of labor. I wouldn't mind more money, but who would? I got myself a degree, I work hard, and I take home a decent paycheck. I put some into a retirement fund, and at some point when I have more of my debt paid off, will start putting more into more savings accounts. If I get cancer and none of my family can afford to pay for it (or wants to pay for it), then I die. My wife would have life insurance payments to help take care of the children and pay off the mortgage, because I was smart enough to pay for some, and life moves on. If a person puts their family's financial state into danger because he didn't pay for life insurance, or assure them other means for survival should he pass, then that is his fault.
If you "didn't want to pay for cancer", there's a good chance your life insurance has a clause that would let them rule that suicide or something, I'd check that. (Suicide means they don't have to pay out)
Also, one of the big reasons why a cancer care bill might run into the hundreds of thousands is because many people never pay their hospital bills. Remove that leech of the system, and you'd have much smaller and more manageable bills for the people who actually do pay them.
Single payer effectively fixes this, as the hospital gets payed regardless of the customer.
So, according to that graph, for every $1 put in to the system in those areas, the government collects that amount back in taxes at some eventual point in time? Genuine question - just trying to figure out exactly what is being shown there. Return on investment for who?
If that is the case, that my life insurance would rule non-treatment of cancer as a suicide, then it is my own fault for not doing proper due-diligence and reading all of the fine print of my life insurance policy. If I wanted insurance that covered such instances, then I should continue looking until I find it.
Single payer would work, if it wasn't so dang inefficient. Problem is, it still spawns leechers. People who think they're sick, and go to the emergency room "just in case," when a simple call to their doctor would have sufficed and been more efficient for the system as a whole. Now the single payer is stuck with a much larger emergency room bill, instead of society as a whole paying nothing for a simple doctor's call. Not to mention the people who had to wait longer to get in to the emergency room because of people visiting on a "just because I can" basis.
If there's no consequence to using the system (if people don't have to pay for visits to the doctor/hospital), then there's no reason they shouldn't go there and receive the maximum benefit possible as often as possible. Which is inefficient for the system, causes waste, and causes overall healthcare costs to go up.