CEOs who can't sit still: Jack Dorsey's Twitter departure is a sign

Jack Dorsey, who is stepping down after six years as Twitter's chief executive, is one of the tech leaders who seem to have grown tired of managing their empires

In 2015, when Jack Dorsey rejoined Twitter as its interim chief executive, he raved about the app with quasi-religious fervor, calling it “the closest thing we have to a global consciousness.” 

But on Monday, Mr. Dorsey left the pulpit. He resigned, saying in an email to Twitter employees that he believed the company should “stand on its own, free of its founder’s influence or direction.” He announced that Parag Agrawal, Twitter’s chief technology officer, would take over as C.E.O., while Bret Taylor would become its board chair. 

In some ways, Mr. Dorsey’s departure is far from surprising. He has faced