I've searched to find a prior explanation of this on another thread and came up empty....To help explain the 72-hour rule and the reason for it's incarnation to those who may still be wondering why it's in place:

I spoke with CO head office recently after they called me back to address a letter I had written. In the letter I addressed the 72 hour rule regarding standby for BF seats. Their response was simple and reasonable:

"A few years ago we noticed that people were bending the rules by making duplicate bookings [albeit under a different name] for the same flight in BF. While they were waiting in line for check-in, they would simply call CO and state they wouldn't make the flight...And miraculously their upgrade request had cleared from the waitlist by the time they checked in for their economy booking"

"Additionally, we found they grey-coats were spending all of their time sorting out disputes about waitlist upgrades and diffusing arguments between pax who were all waitlisted. This was detracting from their ability to perform the concierge duties on board the aircraft which is their primary job function"

Anyway, I wouldn't hope for the 72 hour rule to get reversed anytime soon.

If this has indeed been posted in another thread, please post link to help the moderator close this thread.