You need quite a lot of cash to dine out. If you’re getting wine and things for a few people it can easily be many hundred of dollars in today’s money. Even people who normally carry cash don’t carry that much. What are you going to do in the evening? Go to a bank? They're closed. And if you’re travelling with work and dining out each night, maybe with clients, how much is this adding up to over a month? What other expenses are similar to that? Hotels at the time would invoice or take cheques so you didn’t need cash for those. Paying for restaurants probably seemed a real pain point at the time.