If Alice works 8 hours and exchange her products with Bob's products, which also cost 8 hours to produce, there is no scam involved, just fair trade. Similarly, if the cost to produce certain amount of money is similar to the value of the product those money can purchase, then it is also fair trade. This means, if the amount of goods that need money to trade increases, the cost of producing money should also increase. Bitcoin is a perfect example of the fair trade principle
Profit mandates one receive more value than it (i.e., that one) produces. Money enables one to delude another as to profit's pre-/absence within an economic "exchange" (johnyj).
I don't see how what johny said has anything to do with what you said. Did he say anything about profit?
That said, Imagine Alice works for 8 hours to find and bottle clean water.
Bob spent 8 hours hunting for food.
They exchange 4 hours' worth of water for 4 hours' worth of food. They both profit, because without food, Alice would starve to death, and without water, Bob would die from dehydration.
Value is not necessarily the same for everyone, you can have situations where everyone profit.