In a couple of hours interview it is impossible to flush out all thoughts residing in one’s brain. If it was so, no employee would ever get fired since every one had an interview before and presented a detailed resume.
Only after an employee is hired, it becomes known after several months if it was a mistake. Good executives will admit the mistake and take action.
Sure, if we're talking about the IT guy or the Accouting head at XYZ Corp, I agree. But we're talking about positions like National Security Advisor and Secretary of State. If they're only getting 2-hour interviews....ouch.
I mean, even "Trump people" like Bannon, Lewandowski, Scaramuci and Omarosa are getting the boot after a few months. Maybe it's deserved (or maybe not), but you can't run the White House effectively with all this turnover.