I didn't say they would be successful, but merely 'trying'. If you want to address demand issues or excessive savings you typically look to fiscal policy, but that is basically a non-starter for political reasons. The Fed and many other central banks such as the ECB and BOE are operating basically as the first and last defence with regards to all macro issues.
Is this really what is being addressed here?
It seems more likely that the fed is just pushing harder on the same string.