^ I agree that having a card is infinitely useful when abroad, I think I mentioned some time back on this thread that it's expected for hotels, and useful for larger transactions. And you can withdraw cash with it, too. I always have a credit card when I go abroad.
But, in my experience, cash is king. More often than not, I take and use cash abroad. It's universally accepted and much easier than having a card. I can leave some in the safe in the hotel room, so should I lose it I always have a back-up. I don't have to worry about negotiating foreign ATMs, or not finding an ATM as I've mentioned in my last post. I don't have to think about exchange rates quite as much. And as for paying for dinner, I think you'll find most waiters like a cash tip! (And, indeed, I much prefer giving them their tip in cash).
And I think you are underestimating the difficulties of a lost card when abroad. It's not quite as simple as just getting it cancelled and having a new one couriered out. There's the cost and the time to be considered, not to mention the hassle of dealing with your insurance company. Whilst you're waiting, you won't have any means of payment unless you have some cash. And also the practicalities of doing all of this in another country, where most travellers still don't have the same ready access to the internet as they would in other countries. It's certainly possible to survive, but without some cash you're going to be properly stuck for a few days, and it's going to completely ruin your holiday.
On the other hand, should I lose some cash, it's easier to survive if I've got a card and/or some cash stashed in the hotel safe/elsewhere on my person. It's still cr*p, but I know that I can still get by.
