Watch this…
Radio Free Asia: "did you know in North Korea they eat babies?"
Me: "I don't believe that."
Radio Free Asia: "WHAT?!?!? How did you do that???"
See. And I'm just a dumbass who does nothing but smoke weed and watch pirated b-horror movies. Whats everyone else's fucking excuse?
People fall for this shit because they want to, not because the state department has magical brainwashing powers. Propaganda doesn't mean people don't have fucking agency.
It's the same kind of self-deceiving smugness that eventually lead so many of Reddit's self-styled New Atheists down a reactionary path, where feeling superior to the masses made them believe they were immune to being manipulated, which made many of them easy to manipulate by right-wing cults of personality. 
Such self-deceiving smugness is poison against class solidarity, is hostile toward the people in general because of the bootstrappy attitude built right into it, and leaves the "I'm too smart to be fooled" believer more susceptible to manipulation over time.
I didn't feel it was worth it locking horns with the OP because of prior experience, but I'm glad you put it in your own words better than I would have.
Yeah, it's intimidating and uncomfortable to go against something that your in-group believes. Which, funnily enough, is another reason why propaganda works as well as it does. When a post like this is upvoted heavily, many people are likely to just ignore it or go along with it even if, in a vacuum, they would disagree. Because the threat of being shunned by a community you care about is a powerful deterrent. "You believe propaganda because you want to" is truly such an ignorant statement, it genuinely shocks me that this was upvoted so much.
I think it's more comfortable to buy into because it also covers over even slight hints of discomfort about propaganda that has already been absorbed (especially in entertainment) under pretenses of "this can't possibly have an effect on me, no matter how subtle, because I am too smart for that."