How do you know? Plenty of people work 16 hour days. Of course, it's not for everyone, but it's tough to say what's sustainable for someone else.
Well, sure. All I know is that if I was an investor in Twitter I would not be happy with it.
Don't believe everything you read.
He wasnt CEO at both though
He'd probably rather run Twitter if forced to choose.
Do what, leave them? Or return to them after this?
Spend any real significant time with split duties. Most of his investors would say "We didn't put $x in this with the understanding that you were going to be a 50% CEO/leader"