Why did Adrian suddenly backstab his daughter? He didn't show any signs of disapproval and even if he did where was his plan? You would think the smartest man in the world had thought of something rather than Dr M randomly teleporting him to his lair
My take is He didn't want her getting Dr. Manhattan's powers. In a way it's a kind of character development for him to understand that maybe it takes more than just one person's actions to save the world. I believe he didn't have much of a plan of his own because he'd been awake on Earth for maybe an hour and was at Trieu's mercy. When Jon teleported them, he was back in his element and the wheels started spinning.
EDIT: Or hey if you want to go another way with it, perhaps he was pissed at the idea that she was doing just about all of this to prove she was better than him and he was like "bitch, nobody's better than me".