If nothing else, a credit card gives you a month-long interest-free loan when used properly. That's money in your pocket if you keep the difference in an interest-bearing account. Why wouldn't you take advantage of this?
I'm not sure what hassle/risk you're talking about with a credit card. The hassle factor is the same (approximately none) and the risk is lower, not higher.
People always say this "interest-free loan" thing, but it doesn't make a lot of sense to me. In an average month I spend under €1000 a month on my debit card, but let's round it up to that just for an example. My bank doesn't pay interest on current account balances. Even if I were to go through the hassle of setting up a term deposit for that, the total interest I'd receive on that in one month is 78 cents.
I can think of any number of reasons why I wouldn't bother taking advantage of that.
The question as to whether a credit card is more/less/even risk to a debit card is pretty much the issue at hand here, but even leaving aside the slightly odd issue of psychological risks and hassles, I've heard plenty of horror stories from people in the US where something went wrong to make their monthly payment late (including the credit card company just deciding to change the due date), thus triggering all sorts of badness.
Well, get a better checking account to start with!
Yeah, the money is small, but it's also free. I mean, $10-20/year for doing nothing? Why not?
So as you say, it comes down to the risk differential. If you believe a debit card is less risk, then certainly a tiny amount of interest won't change your mind.
For what it's worth, I've heard far more horror stories about debit cards than credit cards. The major difference is that with a debit card, any company that gets your card info can screw you over. You place an order online, and the company charges you $1000 instead of $10 by mistake, leaving no money in your account. Your next transaction then overdrafts, leaving you with a fat fee. In theory, it's not your fault and you should be able to get the bank or the merchant to cover it, but they'll all be pointing fingers elsewhere....
And of course, if you can't get the money refunded immediately then you spend a great deal of time with no money in your account. Now you may have trouble buying necessities etc. until the situation is fixed.
Additionally, I have my credit cards set up to automatically pay off the full balance each month. If somebody tries to pull a dirty trick and the payment is made late, the blame is clearly and fully with them, so I imagine that would be quickly resolved. Beyond that, there really isn't anything to go wrong other than a major failure of self-control.
Where does one find these magical accounts? In many countries no bank pays interest on current accounts, or, where they do, currently interest rates generally are so low anyway that the amounts are negligible. I have much better ways of arranging my finances than faffing around with credit cards I don't need and moving money around short term money market accounts just to earn less than $20 extra a year.
As for your example of buying something online with a debit card, I don't do that. My bank lets me generate as many virtual cards as I like for online shopping, each with a different number. I set the maximum amount that can be charged to each one and I can then order anything I want online with it with none of the risks you mention.
Even if I couldn't do that, the situation you describe wouldn't arise, as
a) I have daily limits on various types of transfers and withdrawals (that I can adjust online if I need to spend more than that at any time, so I keep the defaults pretty low). So even if someone was being malicious they still couldn't take out more than that amount (and I've SMS notifications set up for all transfers over a fairly low limit too, so they couldn't just come back and take another payment every day until I was cleaned out). It would certainly inconvenience me, but that's just as true with a credit card (and that would probably take me longer to notice). And, as I said earlier, I've had experience of problems with both, and the credit card ones were much more hassle to resolve.
b) my current account is multi-currency, so even if someone managed to clean out all my euros, I'd still have cash in GBP, USD, etc.
c) most of my money isn't in my current account anyway, so even if that got completely cleaned out, in all currencies, I'd still have money in my various other accounts.
I'm not sure what hassle/risk you're talking about with a credit card. The hassle factor is the same (approximately none) and the risk is lower, not higher.