Trump is a disgusting, petty POS. That's the only way to explain this thing.
He's also STUPIDLY petty - this just takes his burned bridges with the FBI at step farther.
Yes, for someone who "needs loyalty, expects loyalty" that badly, Donald Trump is pretty terrible at actually instilling loyalty in his subordinates. Loyalty is never a one-way street.
In my limited experience, this isn't just a problem with Trump but with much (most?) of corporate America.
Upper management always says they expect loyalty, 80-hour work weeks, and so on. Then they turn around, immediately fire a couple dozen people they promised not to fire three months earlier, skip year-end bonuses (except for themselves) and
then get upset when they're badmouthed on industry forums and twitter, and are surprised and unhappy when remaining employees start bailing.