I am asking the OP if his complaint with the Oscars was that a blockbuster didn't win anything or his presumption that it would have won but for its adoption by conservatives as a paean to war? If your complaint is that the Oscars won't award honors to Clint Eastwood due to his politics, you might need to retract that if you have any interest in FACTS. If your complaint is that blockbusters don't often win Oscars and always should, then you are aiming at the wrong target.

Here is the 2013 list of the top 5 moneymakers :
Iron Man 3
Hobbit
The Lone Ranger
Man of Steel
Fast and Furious 6

See any best picture nominees there?

And how is this for the Oscars snubbing war films about American heroes?

2010 top grossing movie Avatar, 2.8 billion dollars nominated for best picture, lost to a small budget, gross 49 million, film for best picture, The Hurt Locker

So your entire premise is wrong. Big movies rarely win, War movies often win, and Clint Eastwood has won when he's done better work including twice for best picture.