I'm afraid it's all part of the nannying world in which we all now live. Even children in a 'walking bus' supervised by umpteen adults in a controlled environment have to wear them!
I even got chastised recently by an Ops Hitler for not wearing it whilst doing a walkround on my OWN aircraft! So just how is a hi-vis vest going to stop me banging my head on the wing of an aircraft I am inspecting? And if I need it for protection against moving vehicles or propellors, I would hope a 5,000lb twin-engined plane would be more visible than I am and if they're close enough to do me damage I'll be running fast before they hit the fuel tanks!!
