787 was designed as a hub buster. It was a business traveller's answer to wonky schedules
The 788 is the wrong airframe for the wrong airline on the wrong routes. Seats are being blocked to limit TOW due to the low thrust eng's/light weight pylons; there goes the profit, (if any), before the brakes are even released.
In any case the C, D & E demographic don't give 2 hoots about what machine they are riding in, all they care about is the $49 Bali/Phuket/Honolulu/LAX/London/moon return.
The business traveller, (read profit), on the other hand does care & they'll pay a premium for it.
Here's a thought, put a red tail on the 788's and replace the 76' with them on the shark patrol. The suits would queue up for this, it might even get close to that 65% folly and would go some way to fix the RIN problem.
All that's needed is a quantum leap in ideology by management and....oh, hang on