It's a Christmas movie...
Going by the standards of Die Hard fans, Rocky IV is a Christmas movie, since it takes place around Christmas time. So is Rocky, Rocky II and Rocky V.
What a special Christmas gift for America in 1985. American Superman defeats the entire Soviet Union in hand to hand combat, leading to the downfall of the USSR empire a mere 5 years later. Also, Rocky had a little help from Rambo in 1988 by pushing the Russians out of Afghanistan. That's my story and I'm sticking to it.