I guess a cynical view (and probably that espoused by the article, which I haven't yet read) is that they're trying to normalize the presence of weaponry in popular fiction as well as in everyday social discourse. If you're in the gun business, you don't want the only people talking about guns to be your critics.

The military also has a stake in glamorizing weaponry and warfighting, and they definitely have a symbiotic relationship with Hollywood in that respect.