@simrin-- I don't think of this quote as saying that at all. I think it's a saying similar to "beauty is in the eye of the beholder."
Many quotes about beauty have the message that physical beauty is misleading. I think this quote is also saying just that, that looks can be deceptive and we shouldn't depend on them to jump to conclusions about people's personality. So your opinions and this quote is saying the same thing.
Ideally this is how all of us should be thinking and acting but it's not so easy. I think that hormones and attraction cause us to jump to conclusions and like or dislike people based on their looks.