I happen to agree with you that burial arrangements are for the benefit of the living, not the dead. But think about the argument (originally made in #475): "her husband HAS been neglecting her... he won't even allow her family to bury her in a Catholic cemetary."
The argument is that husband should have been removed as decision-maker, at least in part, because he has (apparently) indicated that when the time comes he will not allow her remains to be buried in the parents' choice of plots. That simply makes no sense.
First, the decision on plot location hasn't been made; it is prospective only. Husband might change his mind. Second, and more important, it does not bear on husband's ability to make decisions for wife. (If anything, it bears on husband's quite natural antipathy to parents.)
You are also confusing, in my opinion, normal life-sustaining processes such as eating/ feeding, and heroic measures such as heart /lung machines, etc, that replace the bodily functions.