It's not just "will they suck up to and obey Trump".This is the most sensitive job one can have. Is she really the best out there? It's not merit. It's a different sort of DEI - hire those who are Don's Ego Inflators.
Not merit. Not competence.
They also have to dislike the agency as an independent power centre.
Patel's job is to not only use the FBI as a force to harass and threaten Trump's enemies, but also make it something that can't and won't act against Trump and his cronies.
It can't continue to have its own sense of independence and responsibilities outside the president.
Gabbard's role is similar for the intelligence agencies more broadly. They will be broken to Trump's will.
Now, if you think their existence as an independent power centre was bad because they had no reason to be loyal to the interests of the country as a whole or its elected officials, you might see this as a good thing.
Making these powerful forces tools the President can use freely may be a price you think is fine to break the backs of them as a power bloc.
Butler, for instance, considers it a good tradeoff, as he says above.