Because it lets people die.
In some case (assisted suicide), it even CAUSES people to die.
Now, that's frugality! (not)
You’re are right, but you are only half right, and it’s not your fault you are only half right.
Where you are right: Single payer can save money because it rations care, thereby letting people die, and even encourages euthanasia, which causes people to die. However, single payer can cost more money than other ways of providing healthcare on account of waste, fraud, and inefficiency, which come with all government programs.