I've had both dogs AND children, too. Currently sans dog, looking to rectify that, but really quite cautious given the spate of dog thefts, and puppy farming around here. I try to be a responsible dog owner, and that includes procuring them.
No, I don't think that's unusual, sadly, I can think of at least four times I've had cause for concern for myself, my dog, or my kids. And I'm the person who loves a good dobie, german shepherd, staffie or bully.
I think that it's reasonable for people to get to the point where they start thinking about how the hell they defend themselves or their kids.
You're quite right, no dog should be jumping up at anyone, whether, 'oh, Kujo, 'ees lovely, he just wants to be friendly', or not. It's putting dear ol' Kujo at risk of dog vigilantes, as much as anything.