Si is always considered the stick-in-the-mud function, yeah? Tradition, and whatnot. But something's occurred to me, having had the unfortunate opportunity to bear witness to ENFP and ESFP in operation together. Same age, same station, same environment, best friends. The ENFP is faster on the intellectual uptake from my N point of view. The ESFP has the edge, however--quicker to do--which to some degree, forgive me, is more attractive. But...
...the Ni isn't shared.
The ESFP and I both "use" it, but it isn't shared. There's no common history, no common educational background even, and since both of these EPs are Chinese, no shared cultural imagery. I can, it seems to me, recognise the Ni in the ESFP. But without the commonalities, it isn't shared. Superficially attractive, yes. A basis for seeking more understanding, yes. But not shared.
And what's worse, mine's all flexy and bendy and chock full of conscious content, but ESFP Ni is unconscious and disconcerting for the user. If I pull stupid Ni tricks that are outside the ESFP Ni interest... well, I don't know. I guess an ESP gets tired or bored and moves on.
I'd be reckoning it's the same with ENFP and ISTJ: superficial attractiveness that provides a reason for seeking to know more, but that knowing more *could* founder on discovery of some considerable difference of worldview, history, content, understanding, direction, hopes, dreams, etc and so on.
Interesting corollary is that ENFP/INTJ success is based on what is ultimately the more superficial connection when compared to ENFP/ISTJ or ESFP/INTJ.
My theory wins, and always will. If I am not Jung Incarnate then I'm Isabel Myers and I can too wear lipstick if I want. Jung wore lipstick every day of his life.