Reporter explains why Trump's officials won't contradict him

The "rules" bound those who would observe the honor system.  Trump does not know or care about honor or systems, all he cares about is himself.  So, like a king, anyone around him is in danger of losing their position if they merely displease him.  Working around the President is, for many, a once in a lifetime event, unless you're independently wealthy, you're probably going to need a good resume going forward, so there's a palpable risk in being dismissed.  Further, as President, like a king, he wields so much power that he has great influence in places where he hasn't got control thus it's not advisable to get on the bad side of either the king or a president you'd better think carefully and hard before you take a "troublesome" position on any issue(s). Most especially with a loose cannon like Trump who is capable of just about anything.