For a game like AC, I'll take 30fps and better visuals. This new everything must be 60fps move is such utter rubbish. Somehow 99% of the games this gen, and the vast majority of games in all other gens, were unplayable. For certain games, fighters, racers, twitch shooters etc, sure, but for everything? No. Better visuals for many games are still arguably more immersive and important than that extra bump in frame rate, especially in games that are 30fps locked, are slower moving, use effects such as motion blur etc.
Only criticism I have is that AC BF does not look particularly great, so whilst I can excuse 30fps for something like Watch Dogs or KZ SF, especially as launch titles, I can't really for AC BF. It just doesn't look especially graphically advanced, then again, maybe it's far more open than past AC games, and ultimately, it is still a launch title.