We have records of boom-and-bust; and we know what Financial Engineering (a command-and-control economy) does. Or how it does, which is pretty lethargic.
Forcing down interest rates with the Fed's Free Money to member banks (ZIRP) is financial distortion. It results in mis-allocation of resources. One telling example was how General Electric has so-borrowed to buy back its own stock, that a percentage-point raise in interest made the company insolvent. All of a sudden, it owed more than it was worth.
There are many others, but that was one in the news just three months or so ago.
Money is a commodity like any other. The price of money is where borrower and lender agree. Unless you have a command-and-control economy, with the State setting prices. Then you have shortages.
In this case, with artificially-low interest rates, the shortages are in the return on lending and investing. Savers get NOTHING now. Retirees have been living off their principle, since there is little interest proceeds.
Other savers have been pressured (by chasing returns) into extremely-risky investments. Like these junk bonds. Now even THOSE returns are not coming.
IMHO, this "velocity of money" is a fake measurement to obfuscate the real problem, which is a rigged economy. When people have confidence in the future, they trade. And the velocity of money increases.
When they do not, they curtail their purchasing, their hiring, their investing, even. Less velocity of money.
Rigging the game with ZIRP or QE, does nothing to the real problem. Right now, things are going well on the surface, because people have confidence: Because the Kenyan Marxist is gone.
But underneath it all, there's this black hole of government debt that the money-printers are filling. And personal debt is at record levels, too. One ripple in the economy, and a lot of people will be defaulting.