I don't view either as shallow. Everyone has the right to have their own preferences. The ones who view those preferences as shallow are the ones with insecurities about themsves.
A tall guy doesn't generally view a girl as shallow just because she prefers tall guys , the guy who is short in height is more likely to though. The same with girls with small Boobs They are more likely to view a guy as shallow because his preference is bigger Boobs.
People shouldn't be condemned for their own preferences or for what turns them on and off.