JoanH,
First, there is a difference between a rebate and a bonus. On a recent flight, because I was an elite flyer, the senior flight attendant came to me and presented me with a gift - that is a bonus; it was unexpected and never implied that I would be given the gift. Our FF plans are clearly a rebate. The plans clearly state what we must do to earn free tickets, upgrades, and other special privileges. If I do my part, the airline must come through with their promised "rebate".
And as for the flock of people waiting around at the last minute to see if they cleared standby...those are probably the company employees or other non-revs waiting; as they are the last to be given boarding passes.