Credit cards are still more expensive than debit cards, and in Australia any machine that can take the former will take the latter as well. Credit cards allow you to spend money you don't have, whereas debit cards don't.
Sure, credit cards aren't a good product for every person, but your dismissal of them is fairly shallow.
Not all credit cards have annual fees, and those that do usually offer benefits to the card holder that the card holder has determined are worth the cost of the fee.
Interest is only charged if you don't pay your card off each month, and I have mine set up to pay automatically.
They do allow you to spend money you don't have, but they are also isolated from your savings account. My credit card limit is substantially lower than the amount of money in my bank account. A debit card on that account would mean that card fraud actually has an impact on my savings.
In addition in most cases, using a debit card over a credit card network (as opposed to EPTPOS) subjects you to the same rules as using a credit card - you can still end up spending money you don't have, and be liable for it. So your distinction between Credit and Debit cards is actually between credit card networks and the EFTPOS network.
All of which is unrelated to your original point that I was offering a counter-opinion to. Regardless of you personal views on the merits of credit cards, my experience is that Australians use credit cards for in store purchases more often than EFTPOS, and much more frequently than your suggestion of "when they're already living beyond their means".
