Ms. Schiavo's desires are by no means invalid. But as we cannot objectively determine them, as we could if she left a will, we must speculate.
But you make them invalid when you ignore the best authority on what those wishes were, ie. her husband. Learned legal authorities have examined this and made an informed decision. End of story.
But shall we speculate? Maybe ask yourself, would YOU like the idea of being kept alive to spend the rest of your days in a hospital bed as a vegetable fed through a tube, nothing more than a mass of random bodily functions with your higher brain competely gone and no chance of recovery? Well, I wouldn't, and I find it difficult to imagine that any reasonable person would.
You are so willing to take the word of a man with questionable motives over no other evidence of her wishes.
Personally, I'm taking the word of the many judges that looked at the details of the situation and made an informed decision on the case.
A man claims to know my daughter in only a few years in comparison to the 30 years I knew her and he wished to kill her without allowing me to take care of her.
The cardiac arrest that she had 15 years ago and the resulting severe brain damage is what killed her. All the feeding tube was doing was preventing the body from going where the brain already went a long time ago. Terri Schiavo the 'person' died years ago. Let the body go in peace.