Do you not see that this will set up a premise where if a mother/father and spouse disagree on the fate of the person in question, the government can intervene at any point? What if your wife was near death, and the only thing keeping her alive was a respirator? She would surely die without it, but her parents want to keep her alive, despite the fact she won't recover. As her husband, you have the final say of what happens. Do you want a court to take that away? And before you say "this is different", let me assure you that I know. I'm making a point, though.
Most husbands aren't trying to murder their wife.
The court is taking that away at this moment by upholding Terri's man given "right to die". It's already a done deal.