Am I wrong for thinking that the public perception of and attitude towards veterans would be similar to the Vietnam vets when they returned home?
No. During Vietnam many returning veterans who were jaded joined anti war movements and generally were not mistreated. They also were never spat on when they returned. That is another myth.
My suggestion is look up the spitting image about how many myths of the anti-war movements were spread during and after the Vietnam War.
As for the myth of protestors spitting on returning veterans respectively. That did not happen. Because when veterans return they return through military airports and not civilian ones, and thus no protectors could be waiting for them.