its not using Ni, Ni types just often do that sort of stuff due to the nature of being intuitive and preferring intuition in abstractive attitude. people seem to often mix up these things to functions(see functions as being exact slices of common traits of a type).
extraversion and introversion of a function is just about whether you trust the objective or subjective factor more(and since you trust one factor more, you orientate yourself according to it, use it as a starting point for things and compare other things to it(start from it and lead back to it)). so if you trust the objective factor more, that doesent mean that you dont see the subjective one, it just means that you dont trust it. this is why you cant have both Ni and Ne. thats why its stupid to talk of Ni and Ne as separate functions, when its just about intuition as a functions and whether you have objective or subjective attitude towards intuition.
for example i am perfectly capable of seeing the external world and all the details in it etc(which some people think is Se by itself), but i dont blindly trust in what i see, but trust more about my subjective impressions of it. this trust in the subjective impression over what is seen in external world is Si, this does mean that i dont distrust everything i see, its just that it has to be validated first for me to completely trust on it and take it as it seems. and try to find causes behind the things i see, see where they came from, what are the ulterior motives etc etc(this itself is Ne, but i dont blindly trust this either, but i need to think whether these things make sense or not, which is Ti, this way my Ne is supporting my Ti, but Ti is the ultimate judge, hence im Ti dominant).
you see, since i dont trust blindly what the world shows me, there is distrust towards the objective sensations, and since there is distrust towards objective sensations, and trust in subjective ones, i prefer S in introverted attitude and orient myself from it, and this naturally excludes Se, but includes Ne(which again excludes Ni).
edit.
or actually its also a lot about seeing the opposite of preferred attitude as irrelevant by itself, besides not just about not trusting it blindly.
