Debt, deficit and Quantitative Easing are all hollowing out our economy. Our economy is built on a strong base of things of real value. These things are houses, businesses, vehicles, land, human capital, natural resources, among much else. While everything is consumable many things hold their value for many years or even decades, at any given time you can put a worth on everything and come up with a value.
The deficit and debt trades that worth to promises to pay in the future (IOUs). Quantitative easing takes a given amount of capital representated by currency and add currency without adding capital, thus making the capital have to stretch over more dollars. These things hollow out our economy, creating an economic void that is under the surface and hard to see, creating a potential for an economic crash.