I agree that Michael Shumacher is probably alive today because he had money, but I must disagree with your view of the ALS.
There is not much a Doctor can choose not to do here, because there is not much that a Doctor can do here in fact. ALS is a bloddy cursed mess and a really unique disease.
You don't have any (physical) pain so you don't ned pain killers at all. There is not a pill that you can take or receive from a doctor. No screams, no suffering, no blood or self-harm, no urge to stop the pain. You are not troublesome. You are not contagious and wrapped in plastic curtains.
You are not a menace to anybody.
Everybody cries for you.
You are human until the last breath. First you still can talk, look, and understand, then you still can think, or try to communicate. You are not disfigured, not crazy, you are exactly the same people... "in puppet form". (Yes is cruel to say this). As you are still human and retain your intelligence nobody thinks about the idea of killing you,
Is much more easy for a doctor to disconnect a machine when the people is sleeping, totally crazy, in coma. You don't need to look them in the face and think "yes I'm killing you and you know what I'm doing".
This is incredibly horrible for a family, but, as cynic as this could sound, a pretty uncomplicated disease for the job of the doctors.