I think the problem has been one of a failure of 'supply side' economics, even though it has carefully not been mentioned.
The idea is simple enough. You have consumers and investors. All investors are also consumers, about a third of consumers are investors. About .1% of investors are so heavy on the investment side that their consumer side is insignificant.
Anyways, the Fed lowering interest rates is a subsidization of investors. The problem is, investors only invest in stuff that promises a return on their money. Who provides the return? Generally speaking, consumers. If the consumers have no money because of stagnant wages, job exportation, illegal immigrants taking them at low wages, etc... Then there's no place for investors to put the money they're being given, other than inflating what's already there.
This is not always true, but I think it's true in this case. If the economic problems were that investors didn't have enough money to invest, and that was choking the economy, the symptom would be increasing interest rates as they hoover up any available money to invest, to the point where return + risk factor is less than the interest rate. The feds have basically reduced this to return being less than the risk factor is the metric. You can't realistically go lower.
Now, if you free up money for consumers, such as perhaps cutting taxes on people with realistic incomes, they will, on average, spend it. Because they're buying stuff, that creates demand for goods, which creates investment opportunities. Keep in mind that it's possible to overdo this, which would be marked with rising interest rates, inflation in consumer goods(as opposed to investment vehicles), etc...