"That which doesn't destroy you makes you stronger." Or "If it doesn't kill you, it makes you stronger." Nietsche I think is the normal source given for that. He probably got it from some one else though. Probably been have been saying it since the Ice Age, one way and another. Sometimes it's true. You can turn it round the other way - if it doesn't make you stronger, it'll kill you. In time. That's why people have to let go of hatred and bitterness, in order to survive.

I'm not doubting the antagonism to returning vets happened, in fact I'd be surprised if it hadn't. I'd question whether it's best understood as primarily an aspect of the anti-war movement.

People get frightened by the idea of defeat, the same way they get frightened by the idea of bereavement, or any kind of suffering, and they back away, and stay away, and they hit out. I'd imagine, and I'm guessing, that what must really have hurt most wouldn't have been so much the hatred, it'd have been indifference, people turning away and not wanting to know.

At least the people who were actively against the war thought it mattered.