Every dollar is ultimately backed by something. An increase in money supply is not by itself a bad thing, but if those new dollars don't result in the creation

Every dollar is ultimately backed by something. An increase in money supply is not by itself a bad thing, but if those new dollars don't result in the creation of new assets on the other side of the balance sheet, the new money will just shuffle around to eventually map onto the same existing assets. In the worst case, the momentum this creates will cause people to follow suit and throw their savings into the asset market creating a bubble.