I don’t know quite what it is.
My best guess is a combination of several factors:
1) Most of Fox News’s audience is at church
2) Since Fox doesn’t air news on its regular network, people don’t know about it
3) It’s Fox, and because it’s a latecomer largely on UHFs outside the major markets, fewer people CAN watch it
4) People that can and do watch it don’t see anything uniquely “Fox” about it and see it as just an imitator of the other public affairs shows
Also how many people tape or DVD-R it is there anyone of including those in the figures?