But the point of MBTI is that people are different.
I think you are absolutly right about the SJ , NJ thing. We use J on totally different way. But SJ way in much more common in society. So everybody think about J as SJ.What is normal since NJs are actually the rarest types out there.
What is again understandable since those types are "visionary".
On the other hand I see how much smart is the move, that I don't use the full strenght of my J on other people.