If you are poisoned with botulin toxin, you will become unable to breathe, eat, or move. Your heart still beats, and your ability to think is unaffected. The treatment consists of hooking you up to a respirator and giving you a feeding tube. In a few months, you will regain the ability to breathe, eat, and move, and eventually be able to resume a normal life. I'm just pointing out that you can't make a blanket statement about mechanical life support--I think, in cases like botulin poisoning, most people will choose to have the machines, since they know they can hope for a complete recovery. Where mechanical life support is not justified, I think, is in a case where a person is terminal and incurable.
I am not making a blanket statement. I was simply trying to put out there that I did not believe EVERYONE should be on ventilators. I was simply pointing out to someone who disagrees with me that I wasn't extreme in my views wanting to keep everyone on ventilators even when they are dead. I didn't see a need to write down every single instance that I believe or don't believe someone should be removed from life support.