I'm suprised there aren't more red eyes. No slot or gate issues, no traffic, direct routing and its all bonus utilization and productivity, which makes block hour costs over all cheaper. Some airlines like JB used predominately red eyes for a long time to dramatically expand their route footprint with existing airframes. Every long haul international flight is a red eye.

People will build their own 2 airline 20 minute connection itinerary to save a dollar. They will and do fly red eyes and IMO from a marketing perspective we do way too few of them.