The patient cannot make the decision, because she is a minor and demonstrably not mature enough to decide to die.
Yeah, because we all know that when you turn 18 a flip is switched and you magically gain the ability to think rationally
As another poster pointed out, why is not the issue here and so most of the outrage over her reasoning is beside the point. The issue is whether people CAN think rationally, not whether they choose to. A year from now there would be no legal issue at all even if she made the exact same decision for the exact same reasons.
When we are talking about forcing people to accept medication they don't want, I don't find "fuck her freedom, it's good for her" to be a very rational or persuasive argument.
I'd need to see more information about why the justices decided she wasn't mature enough to make this decision herself.