They just didn't do enough, and didn't announce an NGDP level target.
Announcing the target and that the central bank will do whatever it takes, makes the market help with achieving the target--because any difference between a target that will eventually achieved and current reality is an opportunity for arbitrage.
Announcing the target and that the central bank will do whatever it takes, makes the market help with achieving the target--because any difference between a target that will eventually achieved and current reality is an opportunity for arbitrage.