Well... it obviously wasn't "obvious" to Trump, who hired her.
This Omarosa woman was a manipulative bitch from the start. She used Trump and he mistakenly thought she might be an asset for appeal to Black Women.
When he finally saw through her, she turned vindictive.
It was one of Trump's trivial mistakes which turned major only because of the utter depth of her depravity and greed.
So many unworthy people sucked up to Trump when he got elected. It's amazing he made as few mistakes as he did.