"They're just people," Edward points out. "They have to follow rules to avoid getting into fights with other divinity that don't like what they're doing. Plus, there's the whole integrity of the timeline... what do you think it'd do to the fabric of nature if a force as powerful as the Gate went stomping into that world and raising hell at Envy to rescue our alternate?"
Edward's had a little time to brood over this kind of thing.