I find Ni inspiring, and, while I should (theoretically) find Te inspiring too (and maybe even more so), I don't have much of an affinity towards it (or at least haven't realized it yet).
Hence I registered to an INFJ Forum (as opposed to an INTJ forum).
An INTP should not theoretically find Te inspiring. Te is our 5th function, Oppositional Role; this is a function which we can actually use quite well (and thus not find very impressive) but which is still draining and unpleasant to use for very long. We tend to be the most stubborn when using this function, or when faced with those using it not up to our standards.
An INFJ's Fe is our 4th function, Aspirational role, which is underdeveloped but (at least once we gain some maturity) highly valued. We know we are terrible at using it, but deeply want to improve.
INTJs also use Fi in their relief role (which comes out a lot when stressed). Fi is an INTP's devilish function, that which tends to be both the least developed and the least valued. We know we are bad at using this, but rather than wanting to improve we tend to wish everyone could just forget it exists.
Ni is the 6th function, know as the critical parent, senex, or the path to wisdom. We tend to aspire to be good at this function like we do our 4th function (aspirational role, Fe for an INTP), but without such a high energy cost or awareness of our deficiencies. It is common to view our 6th function as almost supernatural.
I tend to think it takes the path to wisdom role much more when paired with the valued aspirational and dominant functions than the disliked oppositional and devilish roles.
It makes sense to me why INFJs would seem inspiring to an INTP, whereas INTJs not so much.
I personally joined the forum after having some of the best conversations of my life with the one confirmed INFJ I know in real life. Also, any INTP forum members seem rather unpleasant.