Heather decided she was done when Elon Musk posted vitriolic attacks on Dr. Anthony Fauci, one of the world's most respected immunologists and outgoing director of the National Institute of Allergy and Infectious Diseases. For Logan, it was when Musk ordered employees to stop paying Twitter's bills to vendors for services they'd already rendered. For Tom, Musk's corrosive and erratic leadership of Twitter since he bought the social media site at the end of October was just too much. And when each of them called to cancel their Tesla car preorders or to terminate their car leases over the past...