I agree, though I would think the ratio is the opposite. The thing is, having multiple cards might be a sign of wealth, but it's also a consequence of local culture. In some countries, everyone has a gazillion of cards. In some countries, having two cards is sort of an exception. In some countries, half the shops usually don't take VISA (Belgium is like that iirc, but I might be mistaken).

So, by taking a decision like that, you're alienating quite a few people, based on non-relevant criteria (not wealth related ones).