It has been a long time since flight attendant was a glamorous job title. The hours are long. Passengers with feelings of entitlement bump up against new no-frills policies. Babies scream. Security precautions grate but must be enforced. Airlines demand lightning-quick turnarounds, so attendants herd passengers and collect trash with the grim speed of an Indy pit crew. Everyone, it seems, is in a bad mood. On Monday, on the tarmac at Kennedy International Airport, a JetBlue attendant named Steven Slater decided he had had enough, the authorities said. After a dispute with a passenger who stood to fetch luggage too soon on a full flight just in from Pittsburgh, Mr. Slater, 38 and a career flight attendant, got on the public-address intercom and let loose a string of invective. Then, the authorities said, he pulled the lever that activates the emergency-evacuation chute and slid down, making a dramatic exit not only from the plane but, one imagines, also from his airline career.