Two of the caverns of time events are based on preventing the development of the current Horde. The culling of Stratholme creates the current world situation which eventually leads to the Wrathgate.
As we all know, and by know I mean have speculated, Nozdormu is the leader of the Infinite Dragonflight. He's altering time to prevent his death. What is his death?
What being is powerful enough and stupid enough to start a pointless fight with the Aspect of Time? Garrosh.
All of the infinite interferences come down to one thing: The development of Garrosh. He has foreseen the rise of a total fucktard. Garrosh is going to kill Nozdormu, probably for no good reason, and Nozdormu seeks to prevent that.
There will be one last attempt: Nagrand, an event which will consist of us killing dragons as they charge toward Garrosh and try to push him into the bonfire. I predict many people will never complete the instance.