It always has amused me that the engineers that fashion these multi-million dollar airplanes using the most advanced mathematics to design the airframes have not yet encountered the bell curve. In any population most people will be of average height and weight; on the extremes of the bell curve will be those who are tiny and skinny and those who are fat and/or tall. Variable spacing in the seating would accommodate everyone without discomfort and without the need to charge extra for those who are big. This is obviously simple but beyond the cretins that design the cabins of commercial airliners. If you're tall or big, don't patronize these idiots; go by car, bus or rail.