I think you hit the nail on the head. "Rot from the top". It happens all the time. Once something good gets going, someone comes in at or near the top and wants to make cost reductions, "improvements", changes, etc. It's really sad how far jetBlue has fallen and when you complain to someone at a higher level at JB all you get is a crap answer. Yes a lot of companies are having issues, but JB seems to stand out as falling apart much worse than the majority of companies. You can't fix a problem if you don't acknowledge a problem. That seems to be the root cause at JB.
One item that really gets me is the app and website both fail with error messages when you go to manage your flight. Your only option is to sit on the phone for hours, wait many hours for a call back, try a chat through your phone, or maybe drive down to a JB office LOL. Really? That particular app/website failure should have been an urgent priority fix. What happened? Nothing. Instead of fixing the issue so thousands of customers don't clog up JB's customer service, JB does nothing to fix the problem.