How much of an uproar would it cause if helicopter passengers were told, 'You're a big guy, so sit by the door. You're a slim guy, so sit by the removable window. You can fit through it easily, and agile enough to do it quickly.'?
Really? You haven't seen our " emergency exit ring" then. Its a template of a type 4 exit. If it fits over you, OK. If not, no fly.