I think the issue isn't the wearing of the watch to the AD, because as you say, the majority wouldn't have a clue form far, or even close distance. Most of the people I have spoken to in AD's are there to sell watches. Most of them don't have as superior knowledge as a few members here about the watches they sell. I feel the problem is when people start waving it about trying to see if they fool them. That's where I think it's ridiculous. I wear reps all the time, if I go into an AD so be it, but I never make a point of flashing in front of them to try and spark a reaction.
I was once outside an AD looking in the window, I had my PO on, and a guy came and stood next to me, noticed the PO and said 'Blimey these Omega's are getting common now aren't they' (tongue in cheek kind of way) then went to show me his blue SM. I just gave a smile and a 'looks that way doesn't'