Well...is it just possible that First Class passengers are dedicated to spending all their waking hours to devising ways of increasing their wealth by even more billions? They just can't spare the time to indulge in such mundane, non-profitable tasks as ablutions. But, to be fair, they may also be so absorbed in trying to come up with practical means to do some good on the planet with their hard-earned money, that the in-flight shower regime completely slips their minds.....
"Happiness is to be able to feed a starving child....bliss is to feed a thousand!"