For me speaking personally, I'd rather the airline I booked with got me to my destination irregardless of the aircraft. I book holidays on destination not the aircraft type! I'm sure most non-ppruners are the same
As horrendous as some of Joe Public can be I'm sure they'd rather be slightly miffed in an older aircraft than to all intents and purpose put themselves in danger flying on a quick fixed 787 (at this point in time at least)
Aircraft subs are just nature of the world. I've flown the LCY-JFK route 8 times and 5 of those I've been subbed onto a 777 because of aircraft problems.
Sure once they've had their first on-board drink, watched a movie or hit the beach/pool that Thomson's customers will forget all about the 787.