I think people are confusing the definition of the word symetrical.
when people talk about someone having a "perfect" face, symmetry is usually included in that definition as well as aspect ratios (features' placement in relation to each other), and the overall look of the features (whether they are 'classic' or not yada yada). in short, there's an actual science to facial perfection, and symmetry is most certainly included in that.
now on a more realistic and personal level, i think it's silly and whatever you consider beautiful is all that matters. it's all a matter of personal taste imo
I saw a special on tv about that a long while back with Elizabeth Hurley.. but I still agree that it is a matter of personal taste. The study of facial traits can go too deep into where certain features originated and it gets complicated where as it doesn't take a scientist to establish your own opinion.