I believe the key to understanding intuitive dominants is to understand how the mind works.
What separates us from animals of lesser intelligence is the interconnection of our neural pathways. Not even the most advanced technologies of today can distinguish between an ant neuron and a human neuron. My favorite neuroscientist, Michael S. Gazzaniga, put the difference kind of something like this:
"Imagine you are in Oklahoma and someone robs a store. He leaves the state, and you are tasked with tracking him down. If you were a police agency equivalent to a whale's brain, it would be like having three federal agents searching different states looking for the perpetrator. If you were a police agency equivalent to a human brain, it would be like being able to search thirty-eight states at once looking for the perpetrator."
Humans are exponentially more capable of tracking and identifying critical information relevant to thought processes, to the point where we can look for five, ten, and twenty 'perpetrators' at a time efficiently. This gives rise to a multitude of advantages over minds capable of only a few simultaneous threads of thought.
Now that some basic physiology of the mind is out of the way, we must look at the Ne/Si - Ni/Se duality. Ne and Se are methods of metabolizing information (from the previous analogy - federal officers), while Ni and Si are methods of recalling information (the perpetrators). Ne users are quick at metabolizing information; I think of it like lightning shooting across existing nodes of Si into the unknown, forging a path to be filled with more nodes of Si. The data generated by this imaginative thought then falls into 'factual' information, which is why I think Ne users are labeled as 'expert classifiers' - kind of like a system of guilty until proven innocent.
Ni users, however, prefer to work and rework the nodes of information already accrued, relying on the direct interpretation of sensory input to provide new nodes to be worked around. To be Ni-dom is to consistently seek nodes of Si that have connections previously unrealized, like turning a stone over four times expecting to see something different on the next flip. They will observe it from the top down and bottom up simultaneously, under a black light, heated up to 300 degrees and then dipped in paint if it meant coming to an objective, definitive conclusion (hence aux Te/Fe - the strive for objective criteria) - in the Se/Ni system, it is kind of like innocent until proven guilty.
I just don't see Ni dominance in many people. I honestly think it manifests itself as a twinge of crazy; I don't think people have the capacity for such mentally exhausting procedure, and statistics apparently back up my perception.