Can aesthetics be objective? If you address a "subjective" issue like aesthetics, statistically, psychologically and neurologically, there are clearly objective aspects to it. However since a portion of the mix is based on life experience and those are quite varied, it will appear almost random and thus resemble a wholely subjective entity.
Another unrelated complication is that there is the phenomenon of painful stimuli triggering a positive response, which though quantifiable, makes the final analysis appear random as it cancels out tradition evaluation.