Actually, we are living through the peak of social penalization of non-conformity.
In days of old, there was an implicit high tolerance for low intelligence and reduced social ability, since communities ware small, lives were short and violent and strong family support was essential for survival. Nobody cared if Larry can befriend a stranger passing through the village, as long as he could work the fields and provide. Only comparatively rare conditions such as schizophrenia or severe autism would lead to ostracization - the proverbial village idiot.
The Larrys of today are many and can be marginalized for minor issues. A low achievement student can be removed from their class and left back, leading to a vicious cycle of depression and economic exclusion. A functional autist has major problems in the modern workplace and the dating scene, leading to hikikomori individuals.
So while the treatment options improved, the bar for what constitutes a well integrated, functioning adult raised even more, without diminishing the stigma for illness.