You could also ask:
Can an inflationary currency really work?
What are the incentives to save or lend your money if it always goes down in value? Does this not stunt economic growth?
Well the thing with that question is that there is an answer to it, yes. As we've seen inflationary currencies do work and they have worked for so long, there's no reason to hold your money (keep too much saved, minus an emergency fund) because if you do the money is always going to be losing value so there's no point to it, inflationary currencies spur economic growth because people go ahead and lend money, invest, etc. Deflationary currencies just have people want to keep their money and have their gains as they don't have to risk anything.