Thoughts come to mind:
1) Boarding completed
2) Crew rostering wakes up to the fact they are short-staffed at SDF.
3) Let's make fools of ourselves by trying to entice boarded pax off the fully-boarded flight, to make room for the deadheading crew that we had overlooked until now.
4) Bidding for vacated seats fails. (Everyone has his price, but we haven't gotten there . . .)
5) Call in the enforcers. Mess up our corporate
PR.