[9x39]

Because you can overheat the economy and cause more damage than good.

We "printed" a lot of money to stop the economy from seizing - the opposite problem - but kept going past what everyone was calling a "soft landing":

https://fred.stlouisfed.org/series/M2SL

Inflation hit pretty bad as a result:

https://fred.stlouisfed.org/series/FPCPITOTLZGUSA