NO ONE with ALS survives 50 years. They clearly put a double in after he died long ago and they have been using his double as a fake "science god" puppet ever since. His generated voice via facial twitches is a total joke as well. The fact that anyone buys this ridiculous "typing with his facial movements" act is beyond me. The whole point of ALS is that you can't control your muscles.. period.
What no one wants to realize is the governments want desperately to sell people on the science as religion meme. They will go to incredible lengths (like even faking Hawking's ongoing life and viability as a scientist) to make this happen.
¯_(ツ)_/¯