Nor, do we want to be silly and accept that all pretty people are wonderful. But appearances can be deceiving as people learn in life. Alien appearances can sometimes change form, shape, or disappear, as many abductees know. You don't know at first. Use the same skills in judging an Alien that you use when meeting a stranger for the first time.
Aliens are like people in that respect.
Aliens are all different, with different appearances, different purposes, and come from different cultures. Their differences are what we want to know more about. Now, this is not to say all Aliens are bad, or that all beautiful Aliens are bad. Perhaps the Nordic types are the good ones. Looking like the Nordics might gain them quicker acceptance than their real appearance, which might be odd, ugly, or even scary.