Maybe all the ISTJs I've been close to have higher Fi, and the ISTJs I've known with lower Fi I've managed to avoid in a personal context. In fact, I'm pretty sure I know this old guy who is an ISTJ who does totally nice things for me all the time, like it's his job or something, because he's old and he thinks that's how old men are supposed to be, and it's his duty, and he feels fantastic about being helpful.
I always felt that way about my grandfather, like he felt really fantastic about his ability to provide or protect or whatever, like he gloated about it, like when he said "no reason to thank me" he really fucking meant it, he got something out of it, made him feel powerful.
ISTJs have never actually hated or judged me that I've noticed, when they have, they've been so unimportant I just ignored them. I hardly even notice INTJs IRL, but when I have, I've done most of the work in the beginning I've noticed, and I'm not so sure I like that. I feel like I've been very very coldly judged by an INTJ and it's a hard thing to shake, and one of the things that makes it easier is an ISTJ saying to me "he's a nasty immoral person, anyway."
Maybe I need too much reassurance to ever be happy around an INTJ. I can tell you I find some of them on-line VERY amusing, but ISTJs can also be quite amusing.
The dynamic is all wrong for me, I'm pretty sure. I always get the feeling I'm nice but don't especially matter, or don't matter at all.