I kind of liked the Colonel exactly because he was such a stereotype, but he was an inversion of the hero stereotype in action movies: unstoppable bad-ass, walks calmly away from the exploding wreckage of his own vehicle, manages to kill the giant leopard monster, that whole scene with him holding his breath while they were escaping (same scene you mentioned). There was no depth - none at all - but he was almost hysterically awesome as an action movie character. I think that's kind of what he was there for - to provide periodic doses of testosterone to hold the jughead demographic over until shit started exploding.
I think we generally agree on him - I just enjoyed him because of his one-dimensionality, because it's a dimension I enjoy so much.
I remember quite a few people cringing and looking away when the assault on the Hometree started, and even Evil Corporate Guy seemed to question things. The Colonel was the only one who was just flat-out reprehensibly evil.
I wanted to be bored or even offended by the whole "evil military industrial complex" angle, but then me and my wife talked about it on the walk home and we came to the conclusion that, as a story about colonialism, it's actually true to life - every single colonial society has done that sort of thing to aboriginal peoples, with about as much remorse