I don't know why everyone thinks Trump would be so awful as the US president. What do they think he's going to do? What makes George W Bush, Obama, and bloody Hillary Clinton so brilliant that only someone of their ilk can do the job? Trump seems anti war, he's not a religious nut, and he certainly is a brilliant, tough negotiator.
I think the real outcry originates from the political careerists, who know that if someone from the world of commerce comes in and does their top job well, they'll be done for.