Heh. You're right, of course. "Good-looking" in general is subjective. However in the article they use a somewhat more objective definition (=not fierce-looking) so everything I said really applies to fierce-lookingness vs. non fierce-lookingness, I guess.
For social animals, I think it can get a little more complicated. Are children born associating desirable traits with certain physical characteristics, or is it something they learn by observing other individuals?