Some petulant part of him would like to insist that there's absolutely no reason why they should and she's just being ridiculous, but the truth is he does understand, even if he doesn't agree, and he's wondered over and over again whether letting the Resistance go in that instance is a concession he should have made. Though, after everything, he suspects she still would have turned against him even if he had.

"She was always alone." It's the first thing he'd seen when he looked into her mind, back then. "Her parents abandoned her on Jakku when she was young, and she spent years waiting for them to come back for her. She sees the Resistance as family she never had--though she barely even knew them at the time."

She'd barely known him, either, if he's honest, but that's beside the point. He had been offering her the belonging she was seeking, in his mind more true than anything the people she'd hardly even fought alongside could offer, and she'd refused it. Because he wasn't good enough for her. He never is. The year that's passed since has done nothing but give her more time to grow close to them, and farther from him.

"And to them, the First Order can never be anything but the enemy."