As an earlier poster noted, there's a difference between classy and "all limbs covered."

My standard summer travel outfit when I fly the night before a meeting is a short sleeve collared golf shirt, pressed extra-long khahki walking shorts, and walking shoes. Why? Because I need that outfit the next morning(s) to get my exercise in before my meetings, and I'll wear my suit on the flight home. This approach gives me the fewest amount of clothes to pack, reiron, etc.; it's a matter of practicality.

I do not understand why the original author would be dismayed at the fact that I would choose to wear walking shorts instead of long dress slacks on my next trip.

Having said that, I must acknowledge my own pet peeves... Going barefoot in the plane. Taking ones shoes off on an evening flight without having changed one's socks before boarding. Unplanned holes in clothing. Excessive amounts of fragrance. So, I can sort of see the original authors' position. But not quite.