JW411,
I can't speak for anyone else but my particular bit of "vitriol" is based on the Kemble requirement that ALL occupants of an aircraft have to wear dayglo. This at a place where most visiting aircraft park within a few yards of the gate. If you want to go off somewhere for the day you have to carry them around, a lot of inconvenience for no real benefit.
If you don't all wear them in the aircraft, in the time it takes to get everyone out and suitably clothed, you could be waiting for your coffee in the restaurant.
Anyway, I am not going to equip the aircraft with more than one jacket just so that I can go to Kemble (I know of nowhere else I am likely to go who has this ridiculous rule) so I guess it will be off limits for me.