I actually think I know the guy you are talking about. He was corporate and had this idealized view about what airline flying was. He came from flying a tiny light airplane with lax rules and a pilot group where everyone knew everyone. He went to JetBlue which gears it's training towards lower time pilots. About half of every pilot class is low time, regional first officers, or great attitude but blemishes on their record. That was mostly done for retention purposes. For that reason alone the training is more detailed with zero wiggle room for interpretation.

He didn't like flying heavy airplanes with a stranger, in a structured environment, with rules on when the autopilot MUST be used (for example JetBlue requires its use for RNP), JetBlue is a small airline where you are going to see MCO, JFK, BOS again and again, no interaction with passengers, and staying in crappy airport hotels.... way more issues than the 320 being too simple for him. He didn't truly understand what airline flying was but tried to save face and say it was the airplane.