A lot of people don't even think about it just because it doesn't even reach them or they are already as confused as those which know to tell the propaganda lies from those pieces who are correct. As a mentioned, then things get broadcasted and told on TV late in the evning or late at night, when most people already have to sleep again to get up early for work next day.
Also, think about the effect of mantras: Mantras get told a thousand times, one of these truths only once or twice and then never again. Through the repeating, what do you guess what becomes "the truth" in the end? Right, that shit that the repeat a thousand times. Even if you don't believe in it, it's what you remember most about an issue though.

And even then, still you face the problem: Nobody still has an idea that could work how a "different system" from what they know could look like. That's also an important factor.