Not everybody is. But people who have a large business or a large organization, or are involved at high levels of government have to deal with litigation. Trump gets sued, and he sues back. I think he actually enjoys it. That makes him more qualified for the job of executive, not a thug, and certainly is no part of any excuse for Cruz suggesting Trump brought the thugs on himself as you seemed to suggest.
Trump will have no problem being the chief executive. Just now he said, “I’m going to start pressing charges.”