I can't see this lasting. I see human rights issues and major law suits a plenty.
I think maybe airlines should have larger seats available for those that want to pay a premium for their own comfort but to be forced to pay for two seats...I don't think so. How will having two seats make it more safer also...there are still only two regular length seatbelts. This will be interesting as if they get away with it then others will try also.
As a bigger than average (Oh err missus) fella I think that airlines need to be taken to task on the ergonomics of their seating.
I have been scrunched into unsuitable aircraft seats all my adult life, even when I have flown business those stupid bed things cut off the blood supply to my legs the moment I fall asleep.
In the UK at least there are laws to protect animals from unscrupulous carriers whilst in transit, they are mandated a space relevant to their shape and size.
I reckon that carriers should give dinky people small seats, medium people medium seats and big people big seats, if there is a relative price differential then that would be fair enough, but the current solution of providing the same space to everybody is just a pants idea thought up by a short arsed accountant!