This by Cardiff Garcia is the best explanation of the dangerous contradictions of quantitative easing. Here is an extract:

 QE is good for the economy because:

 1) Signaling channel (reinforces signal of rates policy)

 2) Asset inflation channel

 3) Portfolio rebalancing channel

 4) Bolsters some kinds of extant collateral (houses, riskier assets)

 5) Bigger monetary base => higher inflation expectations

 QE is bad for the economy because:

 1) Signaling effects unclear, easy to bungle signal (see: Bernanke, May-June 2013)

 2.1) Removes rehypothecable collateral from financial system

 2.2) Removes safe asset that’s better than what it gets swapped for (IOER)

 3) Asset inflation mainly helps the people with assets. Also: bubbles!

 4) Causes weird market functioning effects related to Treasury and MBS liquidity

Points 2.1 and 2.2 are that treasury bonds are better collateral for private sector loans than ordinary cash. Swapping bonds for cash is counterproductive.

The same argument was made in a minute by James Wilson in 1859. Wilson was the founder of both The Economist and what would become Standard Chartered (today 11th on the FTSE 100), as well as  a cabinet minister. After the Indian Mutiny he was sent to be the Finance Member on the Council of India. The Indian government's debt had doubled paying for the war against the mutineers/rebels in 1857. Wilson argued that the India Office should not repurchase this debt, rather keep the bonds in circulation as collateral for foreign investment. 

This went against the Victorian values of thrift held by the rest of the Indian government. Wilson was quickly slapped down (and died of dysentry in 1860).