Also, appeal to nature fallacy is not applicable because I'm not making a "good" versus "bad" conclusion. I'm thinking of "mental illness" in terms of whether it's an evolutionary mal-adaptation, not in moral terms.
And while it is true that loners, outliers, and dropouts often contribute great value to society, it is also true that they also often do great harm to society (the bell curve is a bitch). Moreover, the bulk of collective social value is produced by people following the pack/tribe. What happens to the total productivity of society if everyone acts like the loners, outliers, and dropouts?