Galad is probably movie-star good-looking by our standards, but we see movie stars all the time on the screen, and then we have tabloids and red carpet events catching them in less-attractive moments to kill the illusion for us. We're desensitized. But these people have never seen anyone beyond a bunch of dirt-grubbers their entire lives. When they run into someone who naturally looks the way other people would need to work out a lot and take very good care of their hair and clothing to achieve, it is probably a shock which accounts for the reaction.

Another factor could be some sort of alternate ta'veren effect (or at least comparable to ta'veren the way sniffers and wolfbrothers are comparable to channelers), that no one has studied or categorized because they'd be too embarrassed to write the paper.