United Airlines has been in a financial and operating crisis for years, many cancelled flights with made up excuses, combative customer service a "not our problem" attitude. They haven't brought their employees or customers into the problem to help create a permanent solution, and therefore won't achieve one. They have a crisis, but not a Crisis Mentality!
jetBlue had a spike crisis, with many cancellations and people sitting on planes for long hours. They openly acknowledged it, the CEO said publicly he was "mortified", they changed operating procedures, issued a passengers' bill of rights, and inundated their customers with apologies and compensation. Within a week most of their previously happy, but subsequently very disgruntled, passengers were back in the fold. jetBlue will be stronger for taking a crisis situation and turning it into a Positive Crisis.