Not only is the IDB more, it is real money - a check. VDBs are vouchers and those are typically much cheaper for the airline in reality. Favoring IDBs makes no sense whatsoever - it is always better (CS-wise and financially) to get volunteers. This is nuts.

On the delays front I was 4 of 4 significant delays last week (August) and 2 of those were because the aircraft was scheduled in a way that guaranteed a delay (one a 6 minute planned turn and the other a 30 minute planned turn involving International arrival with domestic departure at ORD). If operations are scheduling airframes like that they have no chance. And while I could have been very unlucky, 2 out of 4 being planned for delays from at least the previous evening suggests this is just bad ops planning.