It has nothing to do with "a god" unless you are influenced by religious belief.

It is a perfectly rational response for those who wish to end their lives in the face of interminable suffering. 

Everyone concerned with how they wish to end their life should consider having a personal directive specifying their needs and wants.

It is interesting to note that many religious adherents are willing to put up with any intervention, no matter how futile or painful, to extend their lives regardless of suffering.  You would think that they would be more inclined to let nature take it's course so they can meet their maker sooner.