I also think their religious views come into play a lot with the Duggars. Love one another and all that stuff, follow the commandments....thou shalt not lie, steal, etc.
I know the G's think of themselves as Christians, but sure don't come off as such. I would bet that they spend more time in churches looking for love offerings rather than salvation or inspiration. Not sure about the Roloffs. Roloff sounds Jewish to me. I haven't watched too many of the older Roloff shows, so I don't know anything about their religious beliefs. But of the three TLC families, I think the Duggars are the most religious and that might have something to do with how they treat each other. JMHO