I can see why it was popular, but it didn't excite me much.
A "bimbo" movie, I call it. Visually beautiful, not much content, and the content it did have was cliched. A perfect Hero's Journey. Campbell has a lot to answer for.
The foreign civilised guy makes a better savage than the savages can, only he can unite them. In Hollywood world there are no Geronimos or Shaka Zulus, only... um... hmmm, trying to think of a historical example of a foreigner uniting savages, but guess what, there isn't one. I wonder why. Fictional examples abound - funnily enough, white Westerners have a lot of fantasies of white Westerners uniting savages under their rule.
Now me, I would have thought that the utter destruction of a zillion year-old home to thousands of people would be pretty fucking good at uniting them, but apparently not.
Good thing the Colonel got himself killed in battle, if he'd survived he would have been cashiered - losing half or all his force against a bunch of spear-wielding savages. Maybe when he said "I could have left, but I kinda like it here," what he really meant was, "actually I've quite a bit of tarnish on my brass, am known among my peers as an idiot, and they only sent me here because they thought, it's only spear-wielding savages, not even he can fuck that up." Woops.