I agree. I never wear shorts on a flight but I might go to a diff airline if they didn't allow me to wear shorts & sandals. But that's more due to my wearing jeans or slacks on my flight so that I can pack the smaller things like shorts in my bag so I can avoid checking bags. And I'm also concerned about getting cold on the plane.

If you want a horror story on dress, I went to Hawaii last year on DL, and booked a ticket for a friend on AA cuz it was a couple of dollars cheaper than the DL flight that the rest of us were on. We got bumped twice on the way from our DL flights, so it ended up much cheaper for us, but when we dropped him off at TPA, I noticed that he really STUNK.

He was wearing shorts and ratty shirt, but if I had been on his flight, I would have been much more concerned about his smell on the long flight DFW-HNL. I had no idea that he would have smelled so bad, or I wouldn't have booked him on my other fave airline!