I can kind of get the whole "upstream swimmer" thing. What I don't understand is why, once they've swum upstream and retrieved their bag, they don't just stay put until it's that row's turn to deplane.

Last night I almost got whacked in the face by some guy who slithered back to row 23 from row 8 and then hoisted his suitcase over his head as he muscled his way back to row 8 so he could stand there for another 5 minutes waiting to get off.