I suspect the commenter is either ignorant or just decided to roll in all the terrible sequels...
The first one, yes. But in every sequel to the original, he's transformed into the stereotypical loose-cannon action hero.
Rambo is a franchize. Why not roll in all the sequels? All those were huge when we were kids, and Rambo was synonymous with "macho super-soldier killings thousands on his own with bazookas", not "PTSD soldier back home from Vietnam is persecuted by local authority figures".
That's because you've erased Rambo 2+ from your memory :)