I think that some of the propaganda is intentional. But some of it is just "playing to the crowd." They play up the stereotypes because it sells, plain and simple. They know that if there is anything Americans hate more than America, it's Russia. And then, there are a lot of people working in media who were raised on these stereotypes and have never questioned them, so they just perpetuate them endlessly.
How many times do we see articles about Putin where he is described as "a former KGB agent"? And how often is a similar qualifier used to describe George W. Bush, who was CIA? It's very unbalanced.