Originally Posted by
BobRoss
Are they? Delta carries over 160 million people per year.
Southwest? 101.
American? 85.
United? 81.
Continental? 62.
http://en.wikipedia.org/wiki/World's_largest_airlines
So, yes all things being equal I would expect to see more complaints about DL simply because of their size. I'm not excusing or apologizing for DL behavior, just suggesting that # of complaints (in a subjective forum such as this) is probably not a good indicator of larger trends.
I haven't done any sort of statistical analysis on it, but the FlyerTalker population isn't exactly a "random sample" -- we've got a lot of sampling bias here.

160 million represents the number carried by both Delta
and Northwest in 2009. Now they have one operating certificate, it would be interesting to see a breakdown of passengers carried by operating certificate. Subtract out those carried by Comair, SkyWest, ASA, Pinnacle, etc., and then see who's the largest.