Its not a fact. At all. Just look at the Amex Shop Small thing. I've managed to lunch out at a number of small chains and independent restaurants recently, by paying on my Amex.
Looks like the club are part of Amex Shop Small for July - www.amexshopsmall.co.uk - I wasn't aware, but had signed up all my Amex cards (Amex direct, Lloyds and MBNA all part of it) and got an email straight after purchasing my Newport County ticket - so nice little bonus there. Not sure if...