Which I do by selecting a station from which to collect my ticket from the list provided on a TOC operated website. Minor stations like Woking, London Waterloo, Edinburgh Waverley, London Kings Cross. And where I have then only been able to collect my ticket by queuing at the ticket office rather than using the machine at which I am told by that selfsame website I must collect my ticket from.I don't ignore it, as I said above - it the machine said it takes Amex then it should take Amex for any purpose. However, if it doesn't accept it for purchases then there's no reason it should accept it for TOD. As with any TOD it's incumbent on the passenger to ensure that they can collect their ticket.
I come back to the basics of good retail. If you have a willing customer, make it easy for them to spend their money. Otherwise, they’ll go somewhere else. And, for goodness sake, don’t then blame the customer if their experience isn’t quite right.
If you say you accept Amex, then make damn sure you accept it everywhere that you accept cards. Don’t create whole classes of machine and expect the customer to fathom it out.