Jorge and other Keynesians hate people saving their money because then nobody has a safety net. Without a safety net this necessitates the government to provide it. And there is nothing Keynesians love more than government force.
I don't know enough about Keynes (or Economics) to tell whether I am a Keynesian. But I certainly do not "hate people saving their money", quite the opposite: I wish people (and my compatriots especially) would consume less and invest more. But I would like to see them choose
productive investments; and hoarding currency (or gold) is not productive.
Hoarding currency is bad for the individual, because all currency will lose value eventually. (As you well know, I am sure that will happen to bitcoin, too, even if there may be another bubble or two.) Hoarding currency is also bad for society because it harms the currency, by destabilizing its value.
add inflation so that people don't hoard it (even though Bitcoin currently has a 12% inflation rate and yet people still hold long term).
As any bitcoiner will tell you, that 12% inflation does not discourage hoarders because they know it is temporary. Besides, even in the short and medium term it is (hopefully) offset by the increase in demand. (That is what happened until 2013, in fits and starts; but may not be the case anymore.)
Let me reming people that this discussion started when someone asked for my idea of a good cryptocurrency. Well, among other things, a good cryptocurrency should be designed so that no one will be tempted to hoard it.