a guest... the horse stuff is not theoretical on my part. I have wrangled horses on public trails and worked with a disabled 4H group.
You sir.. would be suprised at how many BIG people there are out there willing to give things a whirl. OH Purps... show me any buy over 7 foot tall that doesnt weight near 300 pounds. This has nothing to do with "weight consistant with height" standards...heavy is heavy.
And yea.. airliners are arranged to make money... but the seats are built to structural standards to make them safe. Some silly shit about weight and deceleration forces and such...
the live loading of the floor the seats ..and the hardware that nails the seats to the floor gets a little slide-rule time in engineering too.
Hill