How come the revolutions never seem to materialize?

I'm honestly not sure which subreddit this would go best in, but my gut feeling is that it would be most amenable here.

I'm really fascinated with resistance movements/activism/revolutions and the like and love reading/watching documentaries/movies/books/etc about them.

Recently I watched Der Baader-Meinhof Komplex (about the Red Army Faction) and The Weather Underground.

In both cases it's easy to understand why the groups, in their respective contexts, thought a world wide revolution was imminent. I can understand how they, at least initially, felt that all society needed was a good nudge and the people would rise up against the system. This obviously never happened.

As I watch the occupy movement and subsequent other movements around the world, I can't help but draw a parallel to the conditions. While Iraq and Afghanistan don't compare in terms of body count to Vietnam, it's still a similarity. I also notice how both groups are railing against the general oppression/injustice (especially economic injustice) of society. It's like they're fighting back against similar issues, despite being decades apart.

What I'm trying to wrap my head around now is why nothing really came of it. The people did not rise up with either the RAF or the Weathermen. While the groups initially enjoyed popular support, they eventually dwindled and were subdued. Both act in alarmingly cultish ways at times. (Though I guess I can understand that, but it just seems silly and naive now.)

Why did their revolutions fail, but others in different times/parts of the world succeed? (That's kind of a rhetorical question. I know at face value that's very Jared Diamond-ish)

Is it because the conditions weren't right in the 60's and 70's as they were in late 18th century France/America or early 20th century Russia? If so, what are the conditions needed? General starvation? Unemployment over %50? (Though I know that wasn't the situation in the 13 colonies at the time of the American rev.) Still, there has to be some general requirements.

How does technology affect the required conditions? Modern states now have vast powers and control, especially in the realm of spin control, in ways the states of previous centuries could only dream of.

My cynical side feels that the answers lie in some combination of the majority of the people being hopelessly invested in the system/cowards/willfully ignorant. In that case they deserve whatever government they get, and are ultimately the agents of their own enslavement.

Thoughts?