Greta won't let go.
I know it's not immediately obvious ... but it's not Greta who won't let it go. SURPRISE!!! It's the public.
Fox, like all networks is a business going for ratings. Greta, goes for ratings. I'm sure her pay is tied to ratings (as are those of O'Reilly, Hume, Hannity, et al).
I never ever watch her because of this very situation.