If anything, Facebook and Twitter acted as pacifiers. While people could use them, they stayed inside rather than get involved in the streets.
Only when the authorities cut the connection did shit hit the fan, as the masses ventured outside to keep up what was happening.
Thinking about it, i suspect Twitter was an artifact of the US mobile market. It provided a way to do mass texts at a low cost.
But as people moved to smartphones and push IM platforms, twitter's reason to exist kinda evaporated.
On top of that they had basically handed the task of innovating over to third parties via their APIs.
I still recall seeing people use Tweetdeck on desktop Windows with multiple columns set up on different topics, hashtags, and people during large events. This to allow them to track the full breath of what was happening at a glance.
Crazy thing is that Twitter did integrate the "column" concept into their service, via lists. But neither their site nor their apps allow us to access those lists in any way similar to Tweetdeck. In contrast, most third party clients will support a column view these days.