And the reason why this is important is because an asset that is not liquid has no utility as a currency. Put another way, if my $1 today would be worth $1.20 tomorrow, it would be in my best interest to "HODL" on to it instead of using it.
This would be a fantastic scenario for me as an individual, in the short term. Eventually, though, I'd have to buy some bread; the problem is that the baker decided to HODL their currency instead of buying flour (because that would be in their own best interest). Everyone would be sitting on heaps of unusable wealth.