The way the theory goes, people need to be encouraged to take risks. To gamble it all on a crazy new business idea that might not work out at all. Risk is the source of all new value. You can do this by making money very cheap and giving very few other otherlets for risk-free dividends.
People will create all manner of crazy businesses. Some will be duds, some will be frauds, and some will be the future. Then to sort out which is which, you have to turn off the flood of money.