You say they're unelected as if they weren't put there by people who were elected, or they're not wanted. When I vote for my representative, I undertand their job is to lobby for the interest of people in my community. That representation ideally results in a law or some other formal instruction which is the product of a compromise between competing interests.

If one of those competing interests can just become president and then blow up any and all compromises whenever he wants, that is a recipe for instability, as the next guy who comes in will do the same, and then no one gets what they want. This is why unitary executive is a terrible idea, it incentivizes every executive to become a dictator because the moment they're out everything flips immediately. This is why I think for the people pushing it, dictatorship is the actual goal, because there's no theory for how their unitary executive creates stability without permanent power.

His job is to execute the laws the Congress passes, not to substitute his own judgement for Congress' when it comes to the laws he wants to execute. He has to execute them all, and that includes funding agencies he personally disagrees with but we all want to work. It's not his country.