you are not wrong with your complaint, it is very real.  now exchange is a profitable business, just imagine if there are thousands of transactions created on your exchange then you are in big profit.  people who make new exchanges or who try new exchanges (buy/sell transactions) are those who are trying to make a "Profit".  In the future, we will see new exchanges continue appearing as well as people continue trying new exchanges, so don't be surprised by this phenomenon..