Of course he's right. Not much point in living with all these moaning spooks just to spite some guy you don't give a shit about.
But how to go about it? Can't control her. It can be difficult to manipulate the mind of the psychically gifted.
Let's see, who else is there. Terezi? Forget about it! What about that guy? Nah. Her? Nope. Not him either.
How about this guy? Unfortunately, you can only control him about half the time.
Then again, that should be all the time you need.