What's low relative to the height of the driver in the kinds of vehicles that typically come equipped with fog lights can be quite high relative to the kinds of vehicles that typically don't. Also, a lot of fog lights don't, from what I can tell, seem to be anywhere near as focused as headlights.

Granted, I'm no expert on fog lights, so I could be misunderstanding the details of the situation. I've never owned them, so I haven't had occasion to know how they're supposed to work. All I really know about them is that they regularly blind me when I'm driving at night.