Had Arnold attempted to maintain his competition size like so many "ex" Pro's do, he probably wouldn't be with us today, or at the very least, he would be highly un-healthy and he would not have made all the cool movies he made after his competitive days were over.
Gotta commend him for NOT trying to make a comeback to the Mr.O Masters ~
Arnold has never lost his self-confidence, so obviously, it was NOT dependent upon how muscular he was in order to maintain that attitude.
How many others can say the same? It looks to me like a majority of the "ex" Pros are still trying to hang on by that thread.... former shadows of themselves.
I'm not sure I would have let myself go the way he did, but with all of his success and money, how would muscle content have made a difference? It's not like he was selling a supplement line or buying into a gym franchise. He doesn't come out at the Arnold Classic in a tank top....