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).
Profit is an accounting term after the arrival of money, and it is based on an assumption that money have constant value, which is not true, it is not necessary to support economy activities. Economy is driven by demand, and its root is desire
Of course, if you use time as a unit of value, then your statement is almost true. Exchange happens because each participants could save more time from it. But not everyone is profit-seeking and I guess majority of people are not