It is not a well established fact that people prefer symmetry of ones ears or nose, over any other thing they like to look at
The bit I've italicised above is your problem here. Nobody is claiming that to be true. What studies have suggested is that,
all else being equal people prefer symmetrical faces. If you take a someone with a fat, bulging neck; squat, flattened nose; bloodshot eyes and receding, wispy hair and compared them to a healthy, trim indivdual with a nice nose, but with slightly wonky ears, most people will pick the wonky-eared guy - no-one disputes this.
However, studies have shown that if you take the same face, and then adjust it on a computer to make it more symmetrical, people will, on average, rate the symmetrical face as more attractive.
Symmetry isn't the be-all and end-all of attractiveness, but it helps.