A second reasonable case is when entering US feom abroad. Passport check at Ohare is slooooooow, so I always make an effort to get there before most others. I usually don't care about exiting plane early, but I do care about maximizing the time spent drinking beer in a lounge, compared to standing in line.

I often fly from Europe to Houston via Chicago, and how early I get out of the transatlantic flight can mean up to 90 minutes less queuing.