It's certainly an issue on many grounds. Safety being the prime one. I think this is a case where the airline should have a policy that ensures oversized persons are safe onboard the aircraft, even if that person doesn't want to recognise the need for it. The situation pictured is not a safe one.
Buying an extra seat if your body mass requires it (for safety and comfort) is no different to many other disabilities\circumstances that require passengers to pay for extra seating. Or to upgrade to a more spacious class to accomodate their needs.
Asking this person to pay for the space he clearly requires is not nearly as embarassing to him or those around him, as travelling in an unsafe and inadequate manner (such as that pictured).
Last edited by AirborneSoon; 8th Dec 2009 at 11:48.