I think survival in an environment is a skill regardless of the environment. I call them "line jumpers." Trump does it too. This quality of ignoring norms. And it's not that they are BAD at diplomacy, they just don't value it. That's not so much a matter of intelligence as it is moral repugnance.
They're BAD people. Not stupid people. Some of them might be good at public service in another environment, but they are coming up in the worst of times so odds are they're just happy to let the chaos continue because it's working for them. I'd like to believe the tide will turn, but chaos is easy.