Strongly disagree with both the sentiment and the effect of the post.
First off, the benefits for US citizens to go kill and die in foreign countries is marginal at best. They get to have a somewhat stable job for a couple years, get broken down and rebuilt by military ideology and then thrown back into civilian life, maybe with some missing limbs or psychological damage. After that they get healthcare sometimes and fake appreciation on the telly. The poster seems to have forgotten the second half of Parenti's argument, "they're sending our kids to die to line the pockets of the rich". The rich don't go to war, they send your unemployed son to war, and as reward he gets a cheap tin badge or an obituary, and you'll be told that that's good.
Secondly, whatever cruel behaviour exhibited by US soldiers is not simply a byproduct of inherent individual traits of the soldier, but are systemic. Every bit of kindness and sense needs to be systematically excised from the mind of the soldier as soon as he enters the training grounds because the US military in itself needs to be as cruel and bloodthirsty as possible. This does not absolve individual war criminals, but to understand it as part of a system of crime older than that soldier, that will outlive him long after he's overextended his usefulness.
So as a sentiment, I think treating US soldiers as beneficiaries of war -- rather than (lesser) victims of a broader economic system that treats the Reserve Army of Labour as just the Reserve Army -- is misguided and inaccurate.
But with regards to effectiveness, one has to keep in mind that Parenti (et al) weren't just saying things to seem morally correct and on the right side of history. They were actively engaging with the public opinion in order to fight back against those wars. There's a tactic to the communication of showing that, not only the war is immoral and incorrect, but whatever benefits you think you'll get from it are a lie. You will die, your son will die, and it'll have been for nothing. Wars bring no benefit to the US working class. Without nuance, the counternarrative presented by the poster actually embelishes US wars and make them look justified from a selfish position. It's incredibly counterproductive.
It takes an enormous amount of courage to actively resist drafts and the war effort from inside the war machine. You'll be gaslit, slandered, attacked, arrested and maybe even murdered. And instead of joining you, some smartpants will just reproduce what amounts to war propaganda dressed in red/black and abstain from the struggle.