Although the DOT metrics tell a lot, compiling TWO lists of the 4-5 worst airlines out of one list of 19-20 a bit much. Half the population of domestic airlines are now on the "worst" lists.

That said, I'm not suprised to see Delta, Comair & ASA down there. Delta's spot is well earned based on their recent & horrible track record with regard to the rate of complaints / travellers. Perhaps this will finally be addressed in the "Year of the Customer" -- any bets?

Comair & ASA are simply there because they are Comair & ASA -- being worst seems to be their birthright.