Whereas unkind people are actively detrimental to society.

Sure they are. They won't be inventing new devices or running successful businesses, but they will probably enrich the lives of anyone in their social circle

Sticking to the context, a smart person with ill intentions may damage the society. For a reference "smartness", assuming being kind or misogynistic is equally likely, the expected worth of a person is still zero, i.e. "isn't of much use to society".

Neither is a smart asshole. How useful to society are those who try to leech money off it in the most efficient ways possible? (I'm talking charlatans and certain branches of banking)