One thing to remember is the international box office has become more important than it had been in previous decades. Where they could make the Soviets or Chinese or any other nationality a villain and no one complained, they now need those markets and cannot afford to take the chance of alienating a potential market.
Actually I'm pretty sure that Soviets aren't the villains in most films these days because with the collapse of the Soviet Union and subsequent end of the Cold War.
I was referencing the use of the Soviets in previous decades, sorry it wasn't clear.