Morally you are right and I agree with you, I think it's utterly repugnant that the airline won't accept cash in a context where there's no reason not to and th

Morally you are right and I agree with you, I think it's utterly repugnant that the airline won't accept cash in a context where there's no reason not to and the situation is so stressful for the passenger. However, the concept of "legal tender" is very limited and unfortunately could not be used here to put pressure on Ryanair. Cash being legal tender only means that it must be accepted as settlement for an incurred debt, which was not the case here. What's more, I seem to remember that technically it only means it in the context of legal disputes, such that the cash will always settle the debt if deposited at the corresponding court (or something like that).