I am kinda surprised at that part. Why would the family be responsible for his costs beyond what insurance would cover? It is not their debt.
I think for the same reason that your family gets control of your assets. Neither transfer is deserved, but if you allow one then you have to also allow the other.
If no will is drawn up, the estate will be transferred to the next-of-kin after all debts are settled.
Debts don't get passed on but they can eliminate the value of estates being transferred.
I think it's perfectly legitimate to question whether any assets or debts should be transferred on death but right now society is such that some people will be depending on that inheritance since they're inheriting the roof that they've been living under all their life.