Recall that the purpose of money printing is to encourage or discourage spending. When the central bank wants to encourage spending, they print money leading to inflation. Inflation encourages people to turn cash into goods and physical assets. This increases spending in the short-run and stimulates the economy.
Krugman is a clown. The purpose of savings is to spend. Savings encourages spending. A rising bitcoin encourages spending and bitcoin business creation. Deflation stimulates the economy.