Japan is stuck in a classic example of a
liquidity trap:
The Bank of Japan has failed and continues to fail to raise expectations regarding the price level, and as a result their efforts have had little traction on the economy. Their Zero Interest Rate Policy is insufficient. This is the nature of a liquidity trap that was well described by Keynes. They need to find a way to break out of it: pursuing austerity would send them plunging into a Great Depression, but they haven't been willing to take the steps necessary to break out of the trap either.
The experience of England over the past few years shows quite well what happens when you pursue austerity before recovering from a recession: they are now in their country's worst depression. You wouldn't have us imitate that kind of European failure, would you?
McArdle's pronouncement is premature, and a bit naive, though with her I'm not surprised. Also notice how it is dated from 2010... alarmism grows stale rapidly.