Interesting question - a couple of thoughts -
1. JetBlue operates a lot of redeye flights not by choice, but because of a limited amount of aircraft. In the rush to open new markets and add service, many of JetBlue's flights operate at less than optimum times....pax looking for low fares have not seemed to mind, but as JetBlue adds more aircraft, look for redeye flying to be reduced, or atleast, for traditionally timed flights to be added in some markets. Southwest, on the other hand, has lots of aircraft to allocate to its routes, and Southwest's fleet is already well utilized over the course of each day. Also remember that most pax on redeyes are there because of lower fares and/or there was nothing else available......to save a couple hundred dollars per ticket, pax will fly at unusual times! Higher fare business travellers tend to avoid redeyes, except in certain markets like the transcon flights.
2. Many of JetBlue's redeyes are on transcon flights, a niche that JetBlue as done surprisingly well with.....transcon is a market where redeyes will work due to timezones and segment length. Westbound, a late departure (say at 900PM allows for a full working day before deparute and a late arrival, but not at such a crazy time. Eastbound is ideal for many, late departure, arrival in time for the next business day. Same can be said for westcoast-Hawaii flights. Southwest is just getting into the transcon/longer haul markets where redeyes make sense and have demand....leaving Oakland at 1000PM and getting into JFK
at 600AM is different than leaving Midway at 1130PM and arriving in Baltimore at 245AM for example.
3. Long ago, traditional carriers offered more redeye flights when point to point flying was emphasized more....these flights were ususally sold at cheaper fares (20 to 25 per cent discount) at had cute names like night coach, deluxe night coach, owly birds, etc. For example, I remember when EA
each had flights from JFK
departing at around 900PM...and the flights were packed especially on weekend evenings (especially NA
601 out of JFK
at 905PM with a 747!). Nowadays, with the greater emphasis on hubs, late flights are less popular since its very difficult for an airline to run a complete bank of flights at a profit at late hours......pax in most markets are not that interested in the late departing/arriving flights.