I would rather clear a house with a M4 or shorter. 20s are tough and put you at a disadvantage working rooms especially if you haven't trained a lot on it. The average tacticool homeowner will get smoked trying to clear their house. You'll need ever advantage you can get and 20" barrel isn't one.
The timing and movie could be a Hollywood anti-gun thing. I haven't seen it. But the man himself was a hero by every measure of the word. He was a Seventh Day Adventist who chose to enlist in the Army as a combat medic and vowed not to kill.