So just who would be in charge of making those "real-world" decisions? This is the argument Hitler used.
1. Who pays?
2. How do you allocate limited resources?
3. If the family of a PVS patient cannot afford her care, do you think the government (i.e., the taxpayers) should pay for it?
4. If so, are you not, in fact, advocating socialized medicine?
5. In socialized medicine, who ends up making decisions on care, and the allocation of limited resources? That's right, government bureaucrats.
Like it or not, whether healthcare is government-run or private, there are finite resources. There are only so many dollars to pay for care. Decisions will be made -- by family, by insurance companies, or by the state -- as to how to allocate those resources.