I think some people read them to judge whether it was really the airline's fault or the poster's. Human nature being what it is, I think there's a slight bias AGAINST the poster from the outset, so that and the second-guessing about what could have been done must be overcome (one common rookie mistake: waiting in line for a rebooking that could be done by calling the 800 number).

That said, you'll still see cases where the airline might play the "weather card" for something not really weather-related (but maybe it was on a so-so weather day). Airlines also have a strong tendency to dribble out bad news in small increments when you suspect that the real situation is worse and they're not saying so.

Finally, the fact that we get these hang-the-moon trips sez something about people in the U.S. not getting enough vacation time. If you can take 3 or 4 trips a year (albeit not as well-funded) like some Europeans, a ruined one doesn't loom as large.