The Atlanta Falcons won today and brought their record up to 4-4. They now lead the NFC South division.
It is not a coincidence that since the NFL went to the current format with eight divisions of four teams each that three times there has been a division winner with a losing record.
When you group the divisions with four teams each, the odds of there being one division of lemons increases. Then, when you add onto that that each team plays only six games within a division with all of rest outside of the division, the chances of all of those four teams finishing with a losing record become that much greater.