Cameron did not call you a mean spirited A-hole, or at least, didn't do it without calling himself one, as well. The movie wasn't even anti-military, in that it made clear in like the first five minutes that the soldiers who flew to Pandora were not Marines fighting to defend their country, but mercenaries fighting for the Company paycheck.

It was definitely anti-corporate greed, but in no more obtrusive way than Weyland-Yutani from the Aliens movies.