One thing that must be remembered about Southwest is that no assigned seats are an essential part of their business. They do that in order to force passengers to get to the gate early, and scramble to get on the plane. As a result, they are able to turn a plane around at the gate -- unload, load, and depart -- faster than any other airline. This is one way they keep costs ultra-low: essential for them since they regard their competition the automobile more so than other airlines.
I flew Southwest - ONCE. IMHO it's just a case of getting what you pay for. If you want to pay the lowest possible price, then you can't really complain about being treated like an animal, since many folks looking to travel ultra cheap are willing to put up with shabby treatment. I'd rather take my business elsewhere, where the pax are treated better.