I am not a Viet Nam vet, but I was horribly treated in the early eighties. As a Marine doing a couple of parades in the midwest we were booed and jeered and had the occassional item thrown at us. Even in the early nineties when I went to school, advisors, employers, and professors marginalized us (A professor told me he was shocked a MArine could comprehend literature. I noted that if we replaced the term “Marine” with woman, black, etc. he’d be out of a job and that the only reason he wasn’t thrown off the balcony we were on was that I possessed self discipline which included not saying inapropriate or insulting things to others). In 98 a girl saw my USMC sticker on the truck and called me a baby killer (I honestly thought she was an old girlfriend I couldn’t remember until I realized she was referring to the sticker). The reason people lash out at US servicemen is they know we are disciplined and are unlikely to do anything violent. Civilians in the South Pacific or Europe did not have the same reaction to the US military approaching as they did concerning the Japanese or the Soviets.
Now I have people profusely thanking me for my service, which actually makes me more uncomfortable. Seems I am comfortable being shot at than praised.
My observation as well. I and several of my riding buddies were stopped at a McDonalds and saw a couple of punks giving some Marines some crap. They were acting all big and bad and it was apparent that they knew very well that the Marines were not going to retaliate for fear of someone reporting them. We walked over and told the punks that we knew the fine young men in uniform were not allowed to harm them but that we were under no such constraints and would happily kick their asses as a way of thanking the Marines for their service. I thought the punks were going to wet themselves. They nearly ran from the place. We got a nice “Semper Fi” from one of the Marines which we considered an honor.