Where are all the ISFJs? Well, you're looking at one right now.
If you want to see more of us, look for very specific, tight-knit forums. I'm part of 3 entirely unrelated, small and particular forums. Being in small communities is a great way I can easily keep track of who I talk to. Or that's one of the reasons anyway. The size of this forum - it's like I'm talking to the entire world!
He has a basic understanding of type theory, but he doesn't frequent forums to talk about it. He spends a bit of time online either gaming, reading or browsing (and occasionally offering very practical advice) on a technical forum that he visits.
I like ISFJs. Practical, responsible, quiet and loyal.