True, but that usually doesn't affect the person next to me (unless they want to Mile Hyatt).
But that's some good lawyering, there, Pru. I'd like to see that case in Court. Very serious discrimination claim if you go after next-seat intruders who intrude upon the seat, but not the ones who intrude upon the seatback.
In any event, I believe you are purchasing "passage" on any vessel, not a specific method of berthing. (Though of course, there's more fare for first class than steerage). I think they should consider it passage, not seating, and simply charge fare by weight - - which makes sense when you have to get all that weight to defy gravity. And then the discrimination between "unsightly" bigness and "approved" bigness would not come into play.
But an extra charge for the alarming package
might. 