Plane and Simple
Okay, so you're on a plane sitting quietly in the tiny square footage you've bought and paid for, when all of sudden the person behind you needs to get out of their seat.
Why should this become my problem? Because they invariably grab the back of MY seat to use as leverage for them to be able to hoist their ass out of 28C.
C'mon... I'm a big gal and I can get out of my seat unaided. So should you.