Ugly and Mean
At least in my culture, individuality is valued highly. So for me, it can be hard to square a group benefit with individual suffering (see sickle-cell anemia, etc).
We tend to try to rephrase the not-necessarily-nice variety of reality in euphemistic terms — everyone is a unique snowflake! Rather than say someone is ugly, we assure them they have a great personality, and some ill-founded sense of justice tells us that if someone has one, they must be lacking the other.
But in fact, some people are both beautiful and have great personalities, and others are both ugly and mean.
"But I thought you were celebrating the ugly ones!" you might exclaim. Indeed I am. And here is where the concept of individuality actually does shine.
We have been speaking in generalities — what benefits a species, statistically; what people find beautiful or ugly, generally. All of that goes out the window when we start talking about individual preferences. Someone that you find ugly and mean someone else may love, and vice-versa.
Just as what is good for the group may not be good for the individual, what is preferred by the group might not be preferred by any particular individual. Nobody has the average 2.3 children (or whatever the number is); there is variance.
And yet, even so, I don't want to paint too pretty a picture. Are there individuals out there who are just totally, unredeemably bad/ugly/rotten? I don't know, but maybe. It's a big world out there.