You are correct that they at least had the impression that they were supported by the American public and that probably helped them psychologically. They also had a distaste for the rear area commandos, War Critical Workers and the 4Fs that stayed home and had a great old time while they risked their lives and saw things that no young person should ever see. In a generation that was conditioned by their culture to suck it up and keep quiet, it would be very difficult to identify and assist those who experienced more than they could handle. The approach taken was and sometimes still is, to take to the bottle and self-anesthetize.
Your description of how we were treated when we got back is accurate and it was damaging. There were no places for us to resolve our problems except with each other. Our campuses were overflowing with know-it-alls and pro-enemy disrupters, our news agencies competed with each other to present the most negative interpretations, and our government acted as though they had no role at all in defending us or helping us recover. We had to deal with things that no other veterans ever had to deal with. I was refused service in a restaurant because I was in uniform – even though I was with my parents and had crutches and a steel full-length leg brace on. I had a woman – a very beautiful woman – spit in my face in front of all my employees at J.C. Penneys when she heard that I had served in Vietnam. I had my fellow workers at Lockheed Aircraft drop sheet metal behind me on the concrete floor to see me flinch and yelled “hit the deck” to roaring laughter. A friend of mine once said that “we knew that our country didn’t love us anymore”.
The movies were just one aspect to add to the mess. They developed the stereotype of the costumed Vietnam veteran loser who either was gibbering coward or a war criminal or a super-lethal nutcase that could go off at any moment. The caricatures have stayed with us, thanks to movies like those we have mentioned and many more. The war as we experienced it was much more conventional than Hollywood wanted everyone to believe. We went out, we searched for the enemy and when we found them, fixed them, pounded them with supporting arms, then annihilated them. We had three enemies; the local VC, the Main Force VC (“Hard core”) and the North Vietnamese Army (“Hard hats’). Each had their own set of capabilities and we had to deal with the differences. You’ll never know from the movies that the enemy had artillery and in some cases, tanks but they did.
The real story has never been told and we have never been depicted as we really were. It’s a shame.