Lots of opinions on this. I can't help but feel that whatever the pros and cons were Biden decided to just do what he wanted. Fuck the consequences is what I see owing to having been knocked out of the running by his own party whey care what the downside is. They weren't there for him so why worry about them. I have a feeling he experienced a massive sense of betrayal, but it's just my opinion. I simply do not know for sure.
Maybe it's just me projecting my own bitterness at all the brain dead in the Democratic party. Oh, he's too old, he did a terrible debate, let's shoot ourselves!