Our real monetary economy only works, because central banks print money. Within an economy expenditures always equal income. When I give you 100 USD, my expenditure is 100 USD and your income is 100 USD. How then can an economy as a whole have a profit?
Only by printing money, which creates an additional income stream from outside of the system. But, printing money doesn`t necessarily mean that we will see inflation in goods, services and assets. At the moment banks are risk averse in granting credits and so they park their excess reserves at the central bank - the printed money goes back to the central bank and the loop is closed. Of course, there could be a time in the future, when the market is flooded with that money and inflation could skyrocket.
STEEM also needs printing money to create STEEM profits. Every STEEM expenditure equals a STEEM income and STEEM profit can only occur if there is an additional STEEM income flow from outside of the system. STEEM that are not used for transactions, can be parked as STEEM SP and are locked for 1 year on average. Again the loop is closed, inflationary forces contained and the purchasing power of STEEM (for USD or maybe goods in the future) stable. The question is, if in the future, unlocked STEEM SP will flood the market.