ALS is different than most other degenerative diseases or accidents, etc. as our minds are still in tact. We can make our own decisions.
Being a doctor he is in a position to negatively influence people. I feel sorry for him thinking life is not worth living.
Yes, everyone has the right to their own thoughts and opinions on this issue and there are many complex factors that influence each persons decision and I respect that. He is likely reacting from the advice he has given numerous patients and now finds himself in a situation where he does not want to appear the hypocrite.
I know, I am speculating about that but I bet I am right based on many years of dealing with medical people. I am extremely thankful I have now found a group who are open and free thinkers.
Some people just can't accept a less than active life while others can adjust and as Barry said, life is all about change and adaptation to new circumstances. That need to be respected, both sides.