I don't have a problem with the concept of removing a feeding tube vs. never using one.

Consider the timeline.

She had the heart attack.
They didn't know the extent of the damage at that time.

Do they say "well, just in case she's brain-dead, lets not bother with a feeding tube?" - of course not.

But once test after test has conclusively proved that no one is home and that she is indeed brain-dead - then it seems more cruel to keep the corpse alive because of a false sense of hope.

If her arm was missing we could all say "oh look, her arm is missing" - but because you see her hair and eyes and face, you have the mistaken belief that some part of her brain still exists when it doesn't.

Not that long ago there was a story of a chicken with its head cut off. A person kept the chicken "alive" for quite a while by force feeding it down the hole in its neck. It's heart kept on beating and it kept on breathing - yet was it really "alive"?

(I know, I know, people aren't chickens - but which story is more macabre?)