Many merchants think that they can make their own rules these days.
I noticed recently that Office Depot branches now ask for ID on electronics transactions over a certain dollar value. I genuinely don't bother to carry ID all the time so had to explain to a branch manager that they didn't have discretion as to whether they took the card or not. He reckoned I was wrong but phoned AMEX who gave him a mouthful! However - the problem is that the ID request comes from the POS register and the staff are following what the register asks for.